This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A269163 #12 Feb 16 2025 08:33:30
%S A269163 0,7,13,14,25,26,27,28,49,50,51,52,53,54,56,63,97,98,99,100,101,102,
%T A269163 104,105,106,107,108,111,112,119,125,126,193,194,195,196,197,198,200,
%U A269163 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
%N A269163 Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton; range of A269160 sorted into ascending order.
%C A269163 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.
%C A269163 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).
%H A269163 Antti Karttunen, <a href="/A269163/b269163.txt">Table of n, a(n) for n = 0..8191</a>
%H A269163 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Rule30.html">Rule 30</a>
%H A269163 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%H A269163 <a href="https://oeis.org/wiki/Index_to_Elementary_Cellular_Automata">Index to Elementary Cellular Automata</a>
%t A269163 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 *)
%o A269163 (Scheme, with _Antti Karttunen_'s IntSeq-library)
%o A269163 (define A269163 (MATCHING-POS 0 0 (lambda (n) (or (zero? n) (not (zero? (A269162 n)))))))
%Y A269163 Complement: A269164.
%Y A269163 Cf. A007088, A269162.
%K A269163 nonn
%O A269163 0,2
%A A269163 _Antti Karttunen_, Feb 20 2016