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A328101
Column immediately right of the middle column of rule-30 1-D cellular automaton, when started from a lone 1 cell.
4
1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0
OFFSET
1
COMMENTS
Equally, column immediately left of the middle column of rule-86 1-D cellular automaton, when started from a lone 1 cell.
FORMULA
a(n) = A000035(floor(A110240(n) / 2^(n-1))).
a(n) = A000035(floor(A265281(n) / 2^(n+1))).
EXAMPLE
The evolution of one-dimensional cellular automaton rule 30 proceeds as follows, when started from a single alive (1) cell:
---------------------------------------------- a(n)
0: 1
1: 11(1) 1
2: 110(0)1 0
3: 1101(1)11 1
4: 11001(0)001 0
5: 110111(1)0111 1
6: 1100100(0)01001 0
7: 11011110(0)111111 0
8: 110010001(1)1000001 1
9: 1101111011(0)01000111 0
10: 11001000010(1)111011001 1
11: 110111100110(1)0000101111 1
12: 1100100011100(1)10011010001 1
13: 11011110110011(1)011100110111 1
For this sequence, we pick the bit immediately right of the center (marked here with parentheses).
MATHEMATICA
Rest@ CellularAutomaton[30, {{1}, 0}, {106, {{1}}}] (* Michael De Vlieger, Oct 04 2019 *)
PROG
(PARI)
A269160(n) = bitxor(n, bitor(2*n, 4*n)); \\ From A269160.
A110240(n) = if(!n, 1, A269160(A110240(n-1)));
A328101(n) = ((A110240(n)>>(n-1))%2);
\\ Use this one if writing directly to a file:
A328101write(up_to) = { my(s=1, n=0); for(n=0, up_to, if(n>=1, write("b328101.txt", n, " ", ((s>>(n-1))%2))); s = A269160(s)); };
(PARI)
A269161(n) = bitxor(4*n, bitor(2*n, n));
A265281(n) = if(!n, 1, A269161(A265281(n-1)));
A328101(n) = ((A265281(n)>>(n+1))%2);
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 04 2019
STATUS
approved