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 A342677 #15 Mar 22 2021 14:59:50
%S A342677 1,5,28,265,3126,46916,823544,16793633,387422677,10001953190,
%T A342677 285311670612,8916464313700,302875106592254,11112103714568680,
%U A342677 437893891601739648,18446779258148749825,827240261886336764178,39346424755299348744797,1978419655660313589123980
%N A342677 a(n) = Sum_{d|n} (n/d)^(n-d+1).
%H A342677 Seiichi Manyama, <a href="/A342677/b342677.txt">Table of n, a(n) for n = 1..386</a>
%F A342677 G.f.: Sum_{k>=1} (k * x)^k/(1 - k^(k-1) * x^k).
%F A342677 If p is prime, a(p) = 1 + p^p.
%t A342677 a[n_] := DivisorSum[n, (n/#)^(n - # + 1) &]; Array[a, 20] (* _Amiram Eldar_, Mar 18 2021 *)
%o A342677 (PARI) a(n) = sumdiv(n, d, (n/d)^(n-d+1));
%o A342677 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=1, N, (k*x)^k/(1-k^(k-1)*x^k)))
%Y A342677 Cf. A294645, A342629, A342675.
%K A342677 nonn
%O A342677 1,2
%A A342677 _Seiichi Manyama_, Mar 18 2021