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 A368505 #10 Jan 07 2024 06:22:21
%S A368505 1,1,6,60,900,18945,536046,19750864,923023368,53456736825,
%T A368505 3758407535410,315059660550756,31005946105301388,3535337355213234025,
%U A368505 461813139285801522870,68448013078470849802560,11415281142784979557384208,2126537819755999634260404945
%N A368505 a(n) = Sum_{k=0..n} n^(n-k) * k^n.
%F A368505 a(n) ~ sqrt(2*Pi) * n^(2*n + 1/2) / (exp(n) * (log(n))^(n+1)). - _Vaclav Kotesovec_, Dec 28 2023
%o A368505 (PARI) a(n) = sum(k=0, n, n^(n-k)*k^n);
%Y A368505 Main diagonal of A368504.
%Y A368505 Cf. A303991, A349836.
%K A368505 nonn
%O A368505 0,3
%A A368505 _Seiichi Manyama_, Dec 27 2023