login

Revision History for A368100

(Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing all changes.
Numbers of which it is possible to choose a different prime factor of each prime index.
(history; published version)
#9 by Michael De Vlieger at Thu Dec 14 16:29:39 EST 2023
STATUS

proposed

approved

#8 by Gus Wiseman at Thu Dec 14 15:53:42 EST 2023
STATUS

editing

proposed

#7 by Gus Wiseman at Thu Dec 14 08:14:16 EST 2023
CROSSREFS

The version for divisors instead of factors is the complement of A355740.

The version for divisors instead of factors is A368110, complement A355740.

#6 by Gus Wiseman at Thu Dec 14 06:52:58 EST 2023
#5 by Gus Wiseman at Thu Dec 14 06:50:07 EST 2023
CROSSREFS

Positions of positive terms in A367771The complement is A355529, odd A355535, binary A367907.

Positions The version for divisors instead of factors is the complement of 0's in A367771 are A355529, odd A355535, binary A367907A355740.

Positions of 1's positive terms in A367771 are A368101, binary A367908.

For a unique choice we have A368101, binary A367908.

A124010 gives prime signature, sort sorted A118914, length A001221, sum A001222.

Cf. `A007716, A055621, `A083323, `A092918, `A300913, A355737, A355739, A355740, A355741, A355744, A355745, `A367901, A367902, `A367903, A367904, ~A367912.

#4 by Gus Wiseman at Thu Dec 14 06:35:57 EST 2023
COMMENTS

Also MM-numbers A prime index of n is a number m such that prime(m) divides n. The multiset partitions satisfying a strict version of the axiom prime indices of n is row n of choiceA112798.

EXAMPLE

The prime indices of prime indices of 2849 are {4,5,12}, with prime factors {{1,12,2},{35},{1,1,2,2,3}}, and there are of the two choices (1,3,12,5,2) and (1,3,2,5,3), the latter has all different terms, so 2849 is in the sequence.

#3 by Gus Wiseman at Tue Dec 12 23:51:43 EST 2023
EXAMPLE

The prime indices of prime indices of 2849 are {{1,1},{3},{1,1,2}}, and there are two choices (1,3,1) and (1,3,2), so 2849 is in the sequence.

#2 by Gus Wiseman at Tue Dec 12 23:28:33 EST 2023
NAME

allocated for Gus WisemanNumbers of which it is possible to choose a different prime factor of each prime index.

DATA

1, 3, 5, 7, 11, 13, 15, 17, 19, 23, 29, 31, 33, 35, 37, 39, 41, 43, 47, 51, 53, 55, 59, 61, 65, 67, 69, 71, 73, 77, 79, 83, 85, 87, 89, 91, 93, 95, 97, 101, 103, 107, 109, 111, 113, 119, 123, 127, 129, 131, 137, 139, 141, 143, 145, 149, 151, 155, 157, 161, 163

OFFSET

1,2

COMMENTS

Also MM-numbers of multiset partitions satisfying a strict version of the axiom of choice.

EXAMPLE

The terms together with their prime indices of prime indices begin:

1: {}

3: {{1}}

5: {{2}}

7: {{1,1}}

11: {{3}}

13: {{1,2}}

15: {{1},{2}}

17: {{4}}

19: {{1,1,1}}

23: {{2,2}}

29: {{1,3}}

31: {{5}}

33: {{1},{3}}

35: {{2},{1,1}}

37: {{1,1,2}}

39: {{1},{1,2}}

MATHEMATICA

prix[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]];

Select[Range[100], Select[Tuples[prix/@prix[#]], UnsameQ@@#&]!={}&]

CROSSREFS

Positions of positive terms in A367771

Positions of 0's in A367771 are A355529, odd A355535, binary A367907.

Positions of 1's in A367771 are A368101, binary A367908.

The version for binary indices is A367906, positive positions in A367905.

A058891 counts set-systems, covering A003465, connected A323818.

A112798 lists prime indices, reverse A296150, length A001222, sum A056239.

A124010 gives prime signature, sort A118914, length A001221, sum A001222.

Cf. `A007716, A055621, `A083323, `A092918, `A300913, A355737, A355739, A355740, A355741, A355744, A355745, `A367901, A367902, `A367903, A367904, ~A367912.

KEYWORD

allocated

nonn

AUTHOR

Gus Wiseman, Dec 12 2023

STATUS

approved

editing

#1 by Gus Wiseman at Mon Dec 11 14:18:49 EST 2023
NAME

allocated for Gus Wiseman

KEYWORD

allocated

STATUS

approved