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 A368016 #8 Dec 08 2023 09:57:04 %S A368016 1,-1,-2,1,23,78,-101,-2837,-16388,-6045,814731,8464784,33033549, %T A368016 -310826557,-7037215394,-63006436867,-89668812445,6772991607814, %U A368016 122867563251423,1051303604754527,-1882817550826828,-228497075285662201,-4133128828646120841,-36299819546242627536 %N A368016 Expansion of e.g.f. exp(exp(x) - exp(2*x)). %F A368016 a(0) = 1; a(n) = Sum_{k=1..n} (1 - 2^k) * binomial(n-1,k-1) * a(n-k). %o A368016 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, (1-2^j)*binomial(i-1, j-1)*v[i-j+1])); v; %Y A368016 Cf. A368017. %K A368016 sign %O A368016 0,3 %A A368016 _Seiichi Manyama_, Dec 08 2023