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 A367653 #9 Nov 26 2023 08:38:05
%S A367653 1,1,2,4,8,16,32,64,128,257,515,1032,2068,4146,8310,16656,33384,66916,
%T A367653 134125,268837,538850,1080064,2164860,4339204,8697416,17432944,
%U A367653 34942268,70037629,140382111,281379296,563991416,1130453878,2265860666,4541648896,9103196384
%N A367653 G.f. A(x) satisfies A(x) = 1 / (1 - x * (1 + x + x^2 + x^3) * A(x^4)).
%F A367653 a(0) = 1; a(n) = Sum_{k=0..n-1} a(floor(k/4)) * a(n-1-k).
%o A367653 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=0, i-1, v[j\4+1]*v[i-j])); v;
%Y A367653 Cf. A127680, A367652, A367654.
%Y A367653 Cf. A367660.
%K A367653 nonn
%O A367653 0,3
%A A367653 _Seiichi Manyama_, Nov 26 2023