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 A252709 #6 Nov 22 2021 09:02:50
%S A252709 0,1,34,2446,315788,66140883,21216724582,10063816019004,
%T A252709 6854671838281696,6482951652242448021,8197210060548767881834,
%U A252709 13365577359964731097098090,27292891758122129732383863668,68341049055686519197950975142247,206830351842829303737616801603098478
%N A252709 Sum_{k=0..n} k^(n+k)*(n-k)^k.
%F A252709 log(a(n)) ~ n*(3*log(n)- log(log(n)) - 1 - log(2) + (log(log(n)) + log(2) - 2) / (2*log(n))). - _Vaclav Kotesovec_, Nov 22 2021
%t A252709 Table[Sum[k^(n+k)*(n-k)^k, {k, 0, n}], {n, 1, 15}]
%Y A252709 Cf. A062817, A252708, A252710.
%K A252709 nonn,easy
%O A252709 1,3
%A A252709 _Vaclav Kotesovec_, Dec 20 2014