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 A357940 #13 Oct 22 2022 14:02:03
%S A357940 1,0,0,0,1,0,0,1,1,0,1,3,1,1,7,6,2,15,25,11,32,90,66,78,302,351,267,
%T A357940 987,1703,1305,3291,7799,7463,11976,34568,43584,51329,151631,249527,
%U A357940 266058,675490,1395375,1586432,3159982,7675720,10132557,16108875,41991096,66170977,91724556
%N A357940 a(n) = Sum_{k=0..floor(n/3)} Stirling2(k,n - 3*k).
%F A357940 G.f.: Sum_{k>=0} x^(4*k)/Product_{j=1..k} (1 - j * x^3).
%o A357940 (PARI) a(n) = sum(k=0, n\3, stirling(k, n-3*k, 2));
%o A357940 (PARI) my(N=50, x='x+O('x^N)); Vec(sum(k=0, N, x^(4*k)/prod(j=1, k, 1-j*x^3)))
%Y A357940 Cf. A357939, A357941.
%Y A357940 Cf. A357904, A357925.
%K A357940 nonn
%O A357940 0,12
%A A357940 _Seiichi Manyama_, Oct 21 2022