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 A347399 #17 Aug 30 2021 09:40:48
%S A347399 1,5,28,261,3126,46688,823544,16777477,387420517,10000003386,
%T A347399 285311670612,8916117272416,302875106592254,11112006826381820,
%U A347399 437893890380862528,18446744073726329093,827240261886336764178,39346408075296925042857
%N A347399 a(n) = A347398(n^n).
%C A347399 This sequence is different from A062796.
%F A347399 a(n) = A347397(n^n) - A347397(n^n-1) for n > 1.
%F A347399 a(n) = Sum_{k=1..n, k^k | n^n} k^k.
%F A347399 If p is prime, a(p) = 1 + p^p.
%o A347399 (PARI) a(n) = sum(k=1, n, (n^n%k^k==0)*k^k);
%Y A347399 Cf. A000312, A062796, A347397, A347398.
%K A347399 nonn
%O A347399 1,2
%A A347399 _Seiichi Manyama_, Aug 30 2021