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 A323280 #32 Jul 04 2022 13:53:10
%S A323280 1,2,19,781,68553,10100761,2236373953,693667946945,286962262702657,
%T A323280 152652510206521921,101513694573289791441,82511051259976074269425,
%U A323280 80480313356721971865934369,92773167329045961244649105633,124768226258051318899374299271601
%N A323280 a(n) = Sum_{k=0..n} binomial(n,k) * k^(2*k).
%H A323280 Seiichi Manyama, <a href="/A323280/b323280.txt">Table of n, a(n) for n = 0..214</a>
%F A323280 a(n) ~ n^(2*n). - _Vaclav Kotesovec_, May 31 2019
%F A323280 From _Seiichi Manyama_, Jul 04 2022: (Start)
%F A323280 G.f.: Sum_{k>=0} (k^2 * x)^k/(1 - x)^(k+1).
%F A323280 E.g.f.: exp(x) * Sum_{k>=0} (k^2 * x)^k/k!. (End)
%t A323280 Table[1 + Sum[Binomial[n, k]*k^(2*k), {k, 1, n}], {n, 0, 15}] (* _Vaclav Kotesovec_, May 31 2019 *)
%o A323280 (PARI) a(n) = sum(k=0, n, binomial(n, k)*k^(2*k));
%o A323280 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k^2*x)^k/(1-x)^(k+1))) \\ _Seiichi Manyama_, Jul 04 2022
%o A323280 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x)*sum(k=0, N, (k^2*x)^k/k!))) \\ _Seiichi Manyama_, Jul 04 2022
%Y A323280 Cf. A062206, A064570, A086331, A242446, A277454, A277456, A308490, A316747.
%K A323280 nonn
%O A323280 0,2
%A A323280 _Seiichi Manyama_, Jan 12 2019