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 A349962 #19 Dec 08 2021 06:48:37
%S A349962 1,3,19,235,4331,104331,3090315,108503819,4403471115,202762761483,
%T A349962 10442762761483,594761064172811,37115108500229387,2518267981703965963,
%U A349962 184577387811646500107,14533484387811646500107,1223459304002440821206283,109651494909968373175414027
%N A349962 a(n) = Sum_{k=0..n} (2*k)^k.
%C A349962 Partial sums of A062971.
%H A349962 Seiichi Manyama, <a href="/A349962/b349962.txt">Table of n, a(n) for n = 0..351</a>
%F A349962 a(n) ~ 2^n * n^n. - _Vaclav Kotesovec_, Dec 07 2021
%t A349962 a[n_] := Sum[If[k == 0, 1, (2*k)^k], {k, 0, n}]; Array[a, 18, 0] (* _Amiram Eldar_, Dec 07 2021 *)
%o A349962 (PARI) a(n) = sum(k=0, n, (2*k)^k);
%Y A349962 Cf. A062970, A062971, A349961, A349963, A349970.
%K A349962 nonn,easy
%O A349962 0,2
%A A349962 _Seiichi Manyama_, Dec 07 2021