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 A357919 #9 Mar 13 2023 16:10:19
%S A357919 1,0,0,1,-1,2,-5,21,-109,671,-4772,38591,-350036,3520830,-38903271,
%T A357919 468490350,-6107642906,85704534787,-1288021805215,20641247413120,
%U A357919 -351374756822383,6332030169529731,-120427840368046909,2410627702030000447,-50661193580285096086
%N A357919 a(n) = Sum_{k=0..floor(n/3)} Stirling1(n - 2*k,k).
%F A357919 G.f.: Sum_{k>=0} (-x)^k * Product_{j=0..k-1} (j - x^2).
%p A357919 A357919 := proc(n)
%p A357919 add(stirling1(n-2*k,k),k=0..n/3) ;
%p A357919 end proc:
%p A357919 seq(A357919(n),n=0..70) ; # _R. J. Mathar_, Mar 13 2023
%o A357919 (PARI) a(n) = sum(k=0, n\3, stirling(n-2*k, k, 1));
%o A357919 (PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, (-x)^k*prod(j=0, k-1, j-x^2)))
%Y A357919 Cf. A357901, A357920.
%K A357919 sign
%O A357919 0,6
%A A357919 _Seiichi Manyama_, Oct 20 2022