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 A349893 #20 Dec 06 2021 03:09:34
%S A349893 1,2,3,7,46,1052,88603,27121965,37004504306,198705527223758,
%T A349893 5595513387083114571,686714367475480207331583,
%U A349893 468422339816915120237104999422,1664212116512828935888786624225704856,31295654819650678010096952493864470025103251
%N A349893 a(n) = Sum_{k=0..n} k^(k*(n-k)).
%H A349893 Seiichi Manyama, <a href="/A349893/b349893.txt">Table of n, a(n) for n = 0..52</a>
%F A349893 G.f.: Sum_{k>=0} x^k/(1 - k^k * x).
%F A349893 log(a(n)) ~ n^2*log(n)/4 * (1 - log(2)/log(n) + 1/(4*log(n)^2)). - _Vaclav Kotesovec_, Dec 05 2021
%t A349893 Table[1 + Sum[k^(k*(n - k)), {k, 1, n}], {n, 0, 16}] (* _Vaclav Kotesovec_, Dec 05 2021 *)
%o A349893 (PARI) a(n) = sum(k=0, n, k^(k*(n-k)));
%o A349893 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-k^k*x)))
%Y A349893 Cf. A117402, A349880, A349881, A349886, A349894.
%K A349893 nonn
%O A349893 0,2
%A A349893 _Seiichi Manyama_, Dec 04 2021