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 A117999 #21 Feb 16 2025 08:33:00
%S A117999 1,6,28,104,496,1568,7360,27520,130304,396800,1848320,6879232,
%T A117999 32706560,103702528,485867520,1799258112,8569421824,25897336832,
%U A117999 120686641152,448682000384,2137705676800,6768178495488,31718320898048,118691479945216,558749693509632
%N A117999 Decimal number generated by the binary bits of the n-th generation of the Rule 110 elementary cellular automaton.
%H A117999 Paolo Xausa, <a href="/A117999/b117999.txt">Table of n, a(n) for n = 0..1000</a>
%H A117999 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Rule110.html">Rule 110</a>
%F A117999 a(n) = A006978(n+1)*2^n. - _Pontus von Brömssen_, Oct 18 2022
%e A117999 1; 1, 1, 0; 1, 1, 1, 0, 0; 1, 1, 0, 1, 0, 0, 0; 1, 1, 1, 1, 1, 0, 0, 0, 0; ...
%t A117999 A117999list[nmax_]:=MapIndexed[FromDigits[ArrayPad[#1,#2-nmax-1],2]&,CellularAutomaton[110,{{1},0},{nmax,All}]];A117999list[25] (* _Paolo Xausa_, Oct 04 2023 *)
%Y A117999 Cf. A006978.
%K A117999 nonn,base
%O A117999 0,2
%A A117999 _Eric W. Weisstein_, Apr 08 2006