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Triangular array T, read by rows: T(n,k) = number of sums |x-y| + |y-z| - |x-z| = k, where x,y,z are in {1,2,...,n}.
+0
12
1, 6, 2, 17, 8, 2, 36, 18, 8, 2, 65, 32, 18, 8, 2, 106, 50, 32, 18, 8, 2, 161, 72, 50, 32, 18, 8, 2, 232, 98, 72, 50, 32, 18, 8, 2, 321, 128, 98, 72, 50, 32, 18, 8, 2, 430, 162, 128, 98, 72, 50, 32, 18, 8, 2, 561, 200, 162, 128, 98, 72, 50, 32, 18, 8, 2, 716
OFFSET
1,2
EXAMPLE
First eight rows:
1
6 2
17 8 2
36 18 8 2
65 32 18 8 2
106 50 32 18 8 2
161 72 50 32 18 8 2
232 98 72 50 32 18 8 2
For n=2, there are 8 triples (x,y,z):
111: |x-y| + |y-z| - |x-z| = 0
112: |x-y| + |y-z| - |x-z| = 0
121: |x-y| + |y-z| - |x-z| = 2
122: |x-y| + |y-z| - |x-z| = 0
211: |x-y| + |y-z| - |x-z| = 0
212: |x-y| + |y-z| - |x-z| = 2
221: |x-y| + |y-z| - |x-z| = 0
222: |x-y| + |y-z| - |x-z| = 0
so row 2 of the array is (6,2), representing six 0s and two 2s.
MATHEMATICA
t[n_] := t[n] = Tuples[Range[n], 3]
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] - Abs[#[[1]] - #[[3]]] == k &]
u = Table[Length[a[n, k]], {n, 1, 15}, {k, 0, 2 n - 2, 2}]
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 1, 15}, {k, 0, 2 n - 2, 2}]] (* array *)
CROSSREFS
Cf. A084990 (column 1), A000578 (row sums), A001105 (limiting reversed row), A368434, A368437, A368515, A368516, A368517, A368518, A368519, A368520, A368522, A368604, A368605, A368606, A368607, A368609.
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Jan 25 2024
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y|+|y-z| = k, where x,y,z are in {1,2,...,n} and x != y.
+0
11
2, 2, 4, 8, 4, 2, 6, 14, 14, 8, 4, 2, 8, 20, 24, 22, 12, 8, 4, 2, 10, 26, 34, 36, 30, 18, 12, 8, 4, 2, 12, 32, 44, 50, 48, 40, 24, 18, 12, 8, 4, 2, 14, 38, 54, 64, 66, 62, 50, 32, 24, 18, 12, 8, 4, 2, 16, 44, 64, 78, 84, 84, 76, 62, 40, 32, 24, 18, 12, 8, 4
OFFSET
1,1
COMMENTS
Row n consists of 2n even positive integers.
EXAMPLE
First six rows:
2 2
4 8 4 2
6 14 14 8 4 2
8 20 24 22 12 8 4 2
10 26 34 36 30 18 12 8 4 2
12 32 44 50 48 40 24 18 12 8 4 2
For n=2, there are 4 triples (x,y,z) having x != y:
121: |x-y| + |y-z| = 2
122: |x-y| + |y-z| = 1
211: |x-y| + |y-z| = 1
212: |x-y| + |y-z| = 2,
so that row 2 of the array is (2,2), representing two 1s and two 2s.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] != #[[2]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}];
v = Flatten[u]; (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A045991 (row sums), A007590 (limiting reverse row), A368434, A368437, A368516, A368517, A368518, A368519, A368520, A368521, A368522.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Dec 31 2023
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y|+|y-z| = k, where x,y,z are in {1,2,...,n} and x != y and y != z.
+0
11
2, 6, 4, 2, 10, 12, 8, 4, 2, 14, 20, 20, 12, 8, 4, 2, 18, 28, 32, 28, 18, 12, 8, 4, 2, 22, 36, 44, 44, 38, 24, 18, 12, 8, 4, 2, 26, 44, 56, 60, 58, 48, 32, 24, 18, 12, 8, 4, 2, 30, 52, 68, 76, 78, 72, 60, 40, 32, 24, 18, 12, 8, 4, 2, 34, 60, 80, 92, 98, 96
OFFSET
1,1
COMMENTS
Row n consists of 2n-1 even positive integers.
EXAMPLE
First six rows:
2
6 4 2
10 12 8 4 2
14 20 20 12 8 4 2
18 28 32 28 18 12 8 4 2
22 36 44 44 38 24 18 12 8 4 2
For n=3, there are 12 triples (x,y,z) having x != y and y != z:
121: |x-y| + |y-z| = 2
123: |x-y| + |y-z| = 2
131: |x-y| + |y-z| = 4
132: |x-y| + |y-z| = 3
212: |x-y| + |y-z| = 2
213: |x-y| + |y-z| = 3
231: |x-y| + |y-z| = 3
232: |x-y| + |y-z| = 2
312: |x-y| + |y-z| = 3
313: |x-y| + |y-z| = 4
321: |x-y| + |y-z| = 2
323: |x-y| + |y-z| = 2,
so that row 2 of the array is (6,4,2), representing six 2s, four 3s, and two 4s.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] != #[[2]] && #[[2]] != #[[3]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 2, 2 n - 2}]
v = Flatten[u]; (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 2, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A011379 (row sums), A007590 (limiting reverse row), A368434, A368437, A368515, A368517, A368518, A368519, A368520, A368521, A368522.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Dec 31 2023
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y|+|y-z| = k, where x,y,z are in {1,2,...,n} and x < y.
+0
11
1, 1, 2, 4, 2, 1, 3, 7, 7, 4, 2, 1, 4, 10, 12, 11, 6, 4, 2, 1, 5, 13, 17, 18, 15, 9, 6, 4, 2, 1, 6, 16, 22, 25, 24, 20, 12, 9, 6, 4, 2, 1, 7, 19, 27, 32, 33, 31, 25, 16, 12, 9, 6, 4, 2, 1, 8, 22, 32, 39, 42, 42, 38, 31, 20, 16, 12, 9, 6, 4, 2, 1, 9, 25, 37
OFFSET
1,3
COMMENTS
Row n consists of 2n positive integers.
EXAMPLE
First eight rows:
1 1
2 4 2 1
3 7 7 4 2 1
4 10 12 11 6 4 2 1
5 13 17 18 15 9 6 4 2 1
6 16 22 25 24 20 12 9 6 4 2 1
7 19 27 32 33 31 25 16 12 9 6 4 2 1
8 22 32 39 42 42 38 31 20 16 12 9 6 4 2 1
For n=3, there are 9 triples (x,y,z) having x < y:
121: |x-y| + |y-z| = 2
122: |x-y| + |y-z| = 1
123: |x-y| + |y-z| = 2
131: |x-y| + |y-z| = 4
132: |x-y| + |y-z| = 3
133: |x-y| + |y-z| = 2
231: |x-y| + |y-z| = 3
232: |x-y| + |y-z| = 2
233: |x-y| + |y-z| = 1,
so that row 2 of the array is (2,4,2,1), representing two 1s, four 2s, two 3s, and one 4.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] < #[[2]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}];
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A006002 (row sums), A002620 (limiting reverse row), A368434, A368437, A368515, A368516, A368518, A368519, A368520, A368521, A368522.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Dec 31 2023
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y|+|y-z| = k, where x,y,z are in {1,2,...,n} and x < z.
+0
11
2, 4, 3, 2, 6, 6, 8, 2, 2, 8, 9, 14, 9, 6, 2, 2, 10, 12, 20, 16, 16, 6, 6, 2, 2, 12, 15, 26, 23, 26, 17, 12, 6, 6, 2, 2, 14, 18, 32, 30, 36, 28, 26, 12, 12, 6, 6, 2, 2, 16, 21, 38, 37, 46, 39, 40, 27, 20, 12, 12, 6, 6, 2, 2, 18, 24, 44, 44, 56, 50, 54, 42
OFFSET
1,1
COMMENTS
Row n consists of 2n-1 positive integers.
EXAMPLE
First six rows:
2
4 3 2
6 6 8 2 2
8 9 14 9 6 2 2
10 12 20 16 16 6 6 2 2
12 15 26 23 26 17 12 6 6 2 2
For n=3, there are 9 triples (x,y,z) having x < z:
112: |x-y| + |y-z| = 1
113: |x-y| + |y-z| = 2
122: |x-y| + |y-z| = 1
123: |x-y| + |y-z| = 2
132: |x-y| + |y-z| = 3
133: |x-y| + |y-z| = 2
213: |x-y| + |y-z| = 3
223: |x-y| + |y-z| = 1
233: |x-y| + |y-z| = 1,
so that row 1 of the array is (4,3,2), representing four 1s, three 2s, and two 3s.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] < #[[3]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 3}];
v = Flatten[u]; (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 3}]] (* array *)
CROSSREFS
Cf. A006002 (row sums), A110660 (limiting reverse row), A368434, A368437, A368515, A368516, A368517, A368518, A368520, A368521, A368522.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Jan 22 2024
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y| + |y-z| = k, where x,y,z are in {1,2,...,n} and x < y and y >= z.
+0
4
1, 1, 2, 3, 2, 1, 3, 5, 5, 4, 2, 1, 4, 7, 8, 8, 6, 4, 2, 1, 5, 9, 11, 12, 11, 9, 6, 4, 2, 1, 6, 11, 14, 16, 16, 15, 12, 9, 6, 4, 2, 1, 7, 13, 17, 20, 21, 21, 19, 16, 12, 9, 6, 4, 2, 1, 8, 15, 20, 24, 26, 27, 26, 24, 20, 16, 12, 9, 6, 4, 2, 1, 9, 17, 23, 28
OFFSET
1,3
COMMENTS
Row n consists of 2n positive integers.
EXAMPLE
First six rows:
1 1
2 3 2 1
3 5 5 4 2 1
4 7 8 8 6 4 2 1
5 9 11 12 11 9 6 4 2 1
6 11 14 16 16 15 12 9 6 4 2 1
For n=3, there are 8 triples (x,y,z) having x < y and y >= z:
121: |x-y| + |y-z| = 2
122: |x-y| + |y-z| = 1
131: |x-y| + |y-z| = 4
132: |x-y| + |y-z| = 3
133: |x-y| + |y-z| = 2
231: |x-y| + |y-z| = 3
232: |x-y| + |y-z| = 2
233: |x-y| + |y-z| = 1
so row 1 of the array is (2,3,2,1), representing two 1s, three 2s, two 3s, and one 4.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] < #[[2]] >= #[[3]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}];
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}]] ((* array *)
CROSSREFS
Cf. A000027 (column 1), A007290 (row sums), A002620 (limiting reversed row), A368434, A368437, A368515, A368516, A368517, A368518, A368519, A368520, A368521, A368522, A368604, A368606, A368607, A368609.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Jan 22 2024
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y| + |y-z| = k, where x,y,z are in {1,2,...,n} and x <= y and y >= z.
+0
4
1, 2, 2, 1, 3, 4, 4, 2, 1, 4, 6, 7, 6, 4, 2, 1, 5, 8, 10, 10, 9, 6, 4, 2, 1, 6, 10, 13, 14, 14, 12, 9, 6, 4, 2, 1, 7, 12, 16, 18, 19, 18, 16, 12, 9, 6, 4, 2, 1, 8, 14, 19, 22, 24, 24, 23, 20, 16, 12, 9, 6, 4, 2, 1, 9, 16, 22, 26, 29, 30, 30, 28, 25, 20, 16
OFFSET
1,2
COMMENTS
Row n consists of 2n-1 positive integers.
EXAMPLE
First six rows:
1
2 2 1
3 4 4 2 1
4 6 7 6 4 2 1
5 8 10 10 9 6 4 2 1
6 10 13 14 14 12 9 6 4 2 1
For n=2, there are 5 triples (x,y,z) having x <= y and y >= z:
111: |x-y| + |y-z| = 0
121: |x-y| + |y-z| = 2
122: |x-y| + |y-z| = 1
221: |x-y| + |y-z| = 1
222: |x-y| + |y-z| = 0
so row 2 of the array is (2,2,1), representing two 0s, two 1s, and one 3.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] <= #[[2]] >= #[[3]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 1, 15}, {k, 0, 2 n - 2}];
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 1, 15}, {k, 0, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A000027 (column 1), A000330 (row sums), A002620 (limiting reversed row), A368434, A368437, A368515, A368516, A368517, A368518, A368519, A368520, A368521, A368522, A368604, A368605, A368607, A368609.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Jan 22 2024
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y| + |y-z| = k, where x,y,z are in {1,2,...,n} and x != y and y < z.
+0
4
1, 3, 2, 1, 5, 6, 4, 2, 1, 7, 10, 10, 6, 4, 2, 1, 9, 14, 16, 14, 9, 6, 4, 2, 1, 11, 18, 22, 22, 19, 12, 9, 6, 4, 2, 1, 13, 22, 28, 30, 29, 24, 16, 12, 9, 6, 4, 2, 1, 15, 26, 34, 38, 39, 36, 30, 20, 16, 12, 9, 6, 4, 2, 1, 17, 30, 40, 46, 49, 48, 44, 36, 25
OFFSET
1,2
COMMENTS
Row n consists of 2n-1 positive integers.
EXAMPLE
First six rows:
1
3 2 1
5 6 4 2 1
7 10 10 6 4 2 1
9 14 16 14 9 6 4 2 1
11 18 22 22 19 12 9 6 4 2 1
For n=3, there are 6 triples (x,y,z) having x != y and y < z:
123: |x-y| + |y-z| = 2
212: |x-y| + |y-z| = 2
213: |x-y| + |y-z| = 3
312: |x-y| + |y-z| = 3
313: |x-y| + |y-z| = 4
323: |x-y| + |y-z| = 2
so row 2 of the array is (3,2,1), representing three 2s, two 3s, and one 4.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] != #[[2]] < #[[3]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 2, 2 n - 2}];
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 2, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A005408 (column 1), A002411 (row sums), A002620 (limiting reversed row), A368434, A368437, A368515, A368516, A368517, A368518, A368519, A368520, A368521, A368522, A368604, A368605, A368606, A368609.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Jan 25 2024
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y| + |y-z| = k, where x,y,z are in {1,2,...,n} and x <= y.
+0
0
2, 3, 1, 3, 6, 6, 2, 1, 4, 9, 11, 9, 4, 2, 1, 5, 12, 16, 16, 13, 6, 4, 2, 1, 6, 15, 21, 23, 22, 17, 9, 6, 4, 2, 1, 7, 18, 26, 30, 31, 28, 22, 12, 9, 6, 4, 2, 1, 8, 21, 31, 37, 40, 39, 35, 27, 16, 12, 9, 6, 4, 2, 1, 9, 24, 36, 44, 49, 50, 48, 42, 33, 20, 16
OFFSET
1,1
COMMENTS
Row n consists of 2n+1 positive integers.
EXAMPLE
First six rows:
2 3 1
3 6 6 2 1
4 9 11 9 4 2 1
5 12 16 16 13 6 4 2 1
6 15 21 23 22 17 9 6 4 2 1
7 18 26 30 31 28 22 12 9 6 4 2 1
For n=2, there are 6 triples (x,y,z) having x <= y:
111: |x-y| + |y-z| = 0
112: |x-y| + |y-z| = 1
121: |x-y| + |y-z| = 2
122: |x-y| + |y-z| = 1
221: |x-y| + |y-z| = 1
222: |x-y| + |y-z| = 0,
so row 1 of the array is (2,3,1), representing two 0s, three 1s, and one 1.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] < #[[2]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 0, 2 n - 2}];
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 0, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A002411 (row sums), A002620 (limiting reverse row), A368434, A368437, A368515, A368516, A368517, A368519, A368520, A368521, A368522.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Jan 20 2024
STATUS
approved
Irregular triangular array T, read by rows: T(n,k) = number of sums |x-y| + |y-z| = k, where x,y,z are in {1,2,...,n} and x != y and y <= z.
+0
0
2, 1, 4, 5, 2, 1, 6, 9, 8, 4, 2, 1, 8, 13, 14, 12, 6, 4, 2, 1, 10, 17, 20, 20, 16, 9, 6, 4, 2, 1, 12, 21, 26, 28, 26, 21, 12, 9, 6, 4, 2, 1, 14, 25, 32, 36, 36, 33, 26, 16, 12, 9, 6, 4, 2, 1, 16, 29, 38, 44, 46, 45, 40, 32, 20, 16, 12, 9, 6, 4, 2, 1, 18, 33
OFFSET
1,1
COMMENTS
Row n consists of 2n positive integers.
EXAMPLE
First six rows:
2 1
4 5 2 1
6 9 8 4 2 1
8 13 14 12 6 4 2 1
10 17 20 20 16 9 6 4 2 1
12 21 26 28 26 21 12 9 6 4 2 1
For n=2, there are 3 triples (x,y,z) having x != y and y <= z:
122: |x-y| + |y-z| = 1
211: |x-y| + |y-z| = 1
212: |x-y| + |y-z| = 2
so row 2 of the array is (2,1), representing two 1s and one 2.
MATHEMATICA
t1[n_] := t1[n] = Tuples[Range[n], 3];
t[n_] := t[n] = Select[t1[n], #[[1]] != #[[2]] <= #[[3]] &];
a[n_, k_] := Select[t[n], Abs[#[[1]] - #[[2]]] + Abs[#[[2]] - #[[3]]] == k &];
u = Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}];
v = Flatten[u] (* sequence *)
Column[Table[Length[a[n, k]], {n, 2, 15}, {k, 1, 2 n - 2}]] (* array *)
CROSSREFS
Cf. A005443 (column 1), A027480 (row sums), A002620 (limiting reversed row), A368434, A368437, A368515, A368516, A368517, A368518, A368519, A368520, A368521, A368522, A368604, A368605, A368606, A368607, A368609.
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Jan 25 2024
STATUS
approved

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