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 A349894 #14 Dec 11 2021 04:29:26
%S A349894 1,0,1,-3,-10,410,42985,-6527829,-24060996846,-6613442955828,
%T A349894 3882375189467092921,235121650953066124724477,
%U A349894 -289337164954511885810252000250,-995208334663809003504695464745010282,13325880481925983143500510271865447222057073
%N A349894 a(n) = Sum_{k=0..n} (-1)^(n-k) * k^(k*(n-k)).
%H A349894 Seiichi Manyama, <a href="/A349894/b349894.txt">Table of n, a(n) for n = 0..52</a>
%F A349894 G.f.: Sum_{k>=0} x^k/(1 + k^k * x).
%o A349894 (PARI) a(n) = sum(k=0, n, (-1)^(n-k)*k^(k*(n-k)));
%o A349894 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1+k^k*x)))
%Y A349894 Cf. A349856, A349857, A349858, A349891, A349893.
%K A349894 sign
%O A349894 0,4
%A A349894 _Seiichi Manyama_, Dec 04 2021