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 A364774 #17 Aug 28 2023 12:02:12
%S A364774 1,2,2,12,180,168,42840,3400480080,3127563600,12444951686140307040,
%T A364774 12370448552746640800,14616061688484808000,13063440952988449472,
%U A364774 12291672850370833024,11994012329620187776,270303456443855225105637298999007589120,84431359962367713768426673527546762857531371484724067759478650915353749433600
%N A364774 a(n) is the periodic part (converted to base 10) on the n-th diagonal from the right of rule-30 1-D cellular automaton, when started from a single ON cell.
%C A364774 See A364773 for comments and links.
%H A364774 Paolo Xausa, <a href="/A364774/b364774.txt">Table of n, a(n) for n = 1..29</a>
%t A364774 A364774list[steps_]:=Module[{d=2Ceiling[Log2[steps]],ca,n=1,p,plen,a={1}},ca=CellularAutomaton[30,{{1},0},{steps,{1-d,steps}}];While[++n<=2(d-1)&&(plen=Length[p=FindRepeat[Flatten[Rest[Split[Diagonal[ca,d-n]]]]]])>=IntegerLength[Last[a]]&&IntegerQ[Log2[plen]],AppendTo[a,FromDigits[p,2]]];a];
%t A364774 A364774list[300] (* Analyzes 300 evolution steps *)
%Y A364774 Cf. A070950, A094605 (periods), A363343 (diagonals), A364773 (base 2).
%K A364774 nonn,base
%O A364774 1,2
%A A364774 _Paolo Xausa_, Aug 06 2023