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 A365338 #67 Sep 22 2023 11:32:03
%S A365338 1,0,1,0,3,1,15,21,106,378,1116,6931,20196,136500,558559,3103191,
%T A365338 18524418,90852217,661904622,3569749659,25657118047,171935108541,
%U A365338 1149965503347,9166884110308,62758177512570,525194926694256,4072360499426311,33295056117878646
%N A365338 Expansion of e.g.f. exp( Sum_{k>=0} x^(3*k+2) / (3*k+2)! ).
%F A365338 a(0)=1; a(n) = Sum_{k=0..floor((n-2)/3)} binomial(n-1,3*k+1) * a(n-3*k-2).
%o A365338 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(sum(k=0, N\3, x^(3*k+2)/(3*k+2)!))))
%Y A365338 Cf. A000296, A365419.
%K A365338 nonn
%O A365338 0,5
%A A365338 _Seiichi Manyama_, Sep 22 2023