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 A252708 #6 Dec 20 2014 16:23:39
%S A252708 2,259,158268,269187906,978285792294,6507711545263297,
%T A252708 71556972889550923184,1209737575506373416337924,
%U A252708 29788382281118324885770212522,1024436101844282730312688949278959,47581802360081733847924522879325619588,2904105920298407789174888476843692390201446
%N A252708 Sum_{k=0..n} k^(n+k)*(n+k)^k.
%F A252708 a(n) ~ 2^n * n^(3*n). - _Vaclav Kotesovec_, Dec 20 2014
%t A252708 Table[Sum[k^(n+k)*(n+k)^k, {k, 0, n}], {n, 1, 12}]
%Y A252708 Cf. A062817, A252709, A252710.
%K A252708 nonn,easy
%O A252708 1,1
%A A252708 _Vaclav Kotesovec_, Dec 20 2014