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 A370991 #11 Mar 07 2024 01:32:02
%S A370991 1,0,0,3,6,10,735,5691,29428,1122696,18159165,190810675,5768268726,
%T A370991 143497346928,2479363382587,73013461310895,2336253676913640,
%U A370991 58015822633914736,1850758447642034553,69357415099500398979,2252468410247071488970
%N A370991 Expansion of e.g.f. (1/x) * Series_Reversion( x*(1 - x^2/2*(exp(x) - 1)) ).
%H A370991 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A370991 a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} (n+k)! * Stirling2(n-2*k,k)/(2^k * (n-2*k)!).
%o A370991 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(1-x^2/2*(exp(x)-1)))/x))
%o A370991 (PARI) a(n) = sum(k=0, n\3, (n+k)!*stirling(n-2*k, k, 2)/(2^k*(n-2*k)!))/(n+1);
%Y A370991 Cf. A370988, A370992.
%Y A370991 Cf. A353998.
%K A370991 nonn
%O A370991 0,4
%A A370991 _Seiichi Manyama_, Mar 06 2024