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 A356963 #9 Sep 06 2022 15:09:18 %S A356963 1,0,0,0,4,10,20,35,2856,30324,205920,1108965,23266540,482882686, %T A356963 6894708184,75981906455,1191424314640,28555511625320,635370500529216, %U A356963 11547272842560969,213976417787571540,5165550420447656050,142251473243071866520,3624660458114853235771 %N A356963 E.g.f. satisfies log(A(x)) = x^3/6 * (exp(x*A(x)) - 1) * A(x). %F A356963 a(n) = n! * Sum_{k=0..floor(n/4)} (n-2*k+1)^(k-1) * Stirling2(n-3*k,k)/(6^k * (n-3*k)!). %o A356963 (PARI) a(n) = n!*sum(k=0, n\4, (n-2*k+1)^(k-1)*stirling(n-3*k, k, 2)/(6^k*(n-3*k)!)); %Y A356963 Cf. A349557, A356785, A356962. %Y A356963 Cf. A356952, A356968. %K A356963 nonn %O A356963 0,5 %A A356963 _Seiichi Manyama_, Sep 06 2022