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 A341331 #22 Apr 28 2021 02:04:48
%S A341331 1,3,18,158,1825,26141,446782,8869820,200535993,5085658075,
%T A341331 142947350986,4410243535402,148156328308105,5382924338773177,
%U A341331 210309307208574750,8791961076113491704,391581231268402937041,18510377905675629883959,925555262359725659407258
%N A341331 a(n) = n^n - (n-1)^n - (n-2)^n - ... - 1^n.
%H A341331 Robert Israel, <a href="/A341331/b341331.txt">Table of n, a(n) for n = 1..386</a>
%F A341331 a(n) = A000312(n) - A121706(n).
%F A341331 a(n) = - A290844(n-1,n) for n > 1.
%p A341331 f:= proc(n) local k; n^n - add(k^n,k=1..n-1) end proc:
%p A341331 map(f, [$1..30]); # _Robert Israel_, Feb 10 2021
%t A341331 a[n_] := n^n - Sum[k^n, {k, 0, n - 1}]; Array[a, 20] (* _Amiram Eldar_, Apr 28 2021 *)
%o A341331 (PARI) a(n) = n^n-sum(k=0, n-1, k^n);
%Y A341331 Cf. A000312, A031971, A080956, A121706, A179297, A179298, A173142, A191686, A290844.
%K A341331 nonn,easy
%O A341331 1,2
%A A341331 _Seiichi Manyama_, Feb 09 2021