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 A353290 #10 Apr 10 2022 03:13:44
%S A353290 1,0,1,2,19,393,15177,939394,85063260,10599342278,1739073390797,
%T A353290 363404567436467,94224446795779884,29683590039199285223,
%U A353290 11167286542016941966714,4945143125245884296040780,2546112368234517215955646341,1508197687055444623135714912377
%N A353290 a(n) = Sum_{k=0..floor(n/2)} (n-k)^(n-2*k) * |Stirling1(n-k,k)|.
%F A353290 G.f.: Sum_{k>=0} x^k * Product_{j=0..k-1} (k * j + x).
%o A353290 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, x^k*prod(j=0, k-1, k*j+x)))
%o A353290 (PARI) a(n) = sum(k=0, n\2, (n-k)^(n-2*k)*abs(stirling(n-k, k, 1)));
%Y A353290 Cf. A343579, A353255, A353256.
%Y A353290 Cf. A353289.
%K A353290 nonn
%O A353290 0,4
%A A353290 _Seiichi Manyama_, Apr 09 2022