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 A356885 #7 Sep 02 2022 18:06:56 %S A356885 1,0,2,3,-4,30,954,6300,6432,424872,18273960,260682840,1754408424, %T A356885 47063118960,2314149100704,54798086299320,773632032345600, %U A356885 20746972036284480,1072205580591921600,36098491880448944640,816375193722964932480,25160238159364392336000 %N A356885 E.g.f. satisfies A(x)^(A(x)^2) = 1/(1 - x*A(x))^x. %F A356885 a(n) = n! * Sum_{k=0..floor(n/2)} (n-3*k+1)^(k-1) * |Stirling1(n-k,k)|/(n-k)!. %o A356885 (PARI) a(n) = n!*sum(k=0, n\2, (n-3*k+1)^(k-1)*abs(stirling(n-k, k, 1))/(n-k)!); %Y A356885 Cf. A184949, A349559, A356786, A356787, A356884. %Y A356885 Cf. A355767. %K A356885 sign %O A356885 0,3 %A A356885 _Seiichi Manyama_, Sep 02 2022