A269163 - OEIS

A269163

Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton; range of A269160 sorted into ascending order.

0, 7, 13, 14, 25, 26, 27, 28, 49, 50, 51, 52, 53, 54, 56, 63, 97, 98, 99, 100, 101, 102, 104, 105, 106, 107, 108, 111, 112, 119, 125, 126, 193, 194, 195, 196, 197, 198, 200, 201, 202, 203, 204, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 221, 222, 223, 224, 231, 237, 238, 249, 250, 251, 252, 385, 386, 387, 388

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OFFSET

0,2

COMMENTS

Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton. The configuration of white and black cells is encoded in the binary representation (A007088) of each number.

The indexing starts from zero, because a(0) = 0 is a special case in this sequence. (Zero is the only number which is its own predecessor).

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..8191

Eric Weisstein's World of Mathematics, Rule 30

Index entries for sequences related to cellular automata

Index to Elementary Cellular Automata

MATHEMATICA

terms = 100; Clear[f]; f[max_] := f[max] = Sort[Table[BitXor[n, BitOr[2n, 4n]], {n, 0, max}]][[1 ;; terms]]; f[terms]; f[max = 2 terms]; While[ Print[max]; f[max] != f[max/2], max = 2 max]; A269163 = f[max] (* Jean-François Alcover, Feb 23 2016 *)

PROG

(Scheme, with Antti Karttunen's IntSeq-library)

(define A269163 (MATCHING-POS 0 0 (lambda (n) (or (zero? n) (not (zero? (A269162 n)))))))

CROSSREFS

Complement: A269164.

Cf. A007088, A269162.

Sequence in context: A120100 A308525 A104217 * A260482 A328254 A347637

Adjacent sequences: A269160 A269161 A269162 * A269164 A269165 A269166

KEYWORD

nonn

AUTHOR

Antti Karttunen, Feb 20 2016

STATUS

approved