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 A114039 #7 Oct 09 2023 17:18:40
%S A114039 1,-1,-2,-16,-257,-6613,-243980,-12155224,-786429623,-64166829085,
%T A114039 -6449457120962,-783277824629140,-113105715390915929,
%U A114039 -19155829563735891169,-3760880464339217383124,-847344181950467763488740,-217159542960607254804746279,-62816327344923649504400271697
%N A114039 Expansion of g.f. 1/Sum_{k>=0} k!*(k!+1)*x^k/2.
%t A114039 nmax=17; CoefficientList[Series[1/Sum[k!*(k!+1)*x^k/2,{k,0,nmax}],{x,0,nmax}],x] (* _Stefano Spezia_, Oct 09 2023 *)
%Y A114039 Cf. A113871.
%K A114039 sign
%O A114039 0,3
%A A114039 _N. J. A. Sloane_, Feb 01 2006