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 A351796 #9 Feb 20 2022 06:43:36
%S A351796 1,1,0,6,36,-1240,36810,-743568,-4441640,2126086272,-201265464330,
%T A351796 13670088101120,-512174277963612,-50655591400627200,
%U A351796 16935777106057251442,-2936123018591228282880,368896773292405165345200,-22278163772113766968557568
%N A351796 a(n) = n! * Sum_{k=0..n} (-k * (n-k))^k/k!.
%t A351796 a[n_] := n!*(1 + Sum[(-k*(n - k))^k/k!, {k, 1, n}]); Array[a, 18, 0] (* _Amiram Eldar_, Feb 19 2022 *)
%o A351796 (PARI) a(n) = n!*sum(k=0, n, (-k*(n-k))^k/k!);
%Y A351796 Cf. A351780, A351795.
%K A351796 sign
%O A351796 0,4
%A A351796 _Seiichi Manyama_, Feb 19 2022