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 A087905 #9 May 17 2018 17:33:29
%S A087905 1,3,8,36,144,1010,5760,50400,416640,4250232,43545600,553106400,
%T A087905 6706022400,95865541200,1410695430144,22720842144000,376610217984000,
%U A087905 6888030445296000,128047474114560000,2587520533615041024
%N A087905 a(n) = n! * Sum_{d|n} (d/n)^d.
%H A087905 G. C. Greubel, <a href="/A087905/b087905.txt">Table of n, a(n) for n = 1..445</a>
%F A087905 E.g.f.: Sum_{k>0} x^k/(k-x^k).
%t A087905 a[n_]:= n!*DivisorSum[n, (#/n)^# &]; Array[a, 50] (* _G. C. Greubel_, May 16 2018 *)
%o A087905 (PARI) {a(n)= n!*sumdiv(n, d, (d/n)^d)};
%o A087905 for(n=1, 30, print1(a(n), ", ")) \\ _G. C. Greubel_, May 16 2018
%Y A087905 Cf. A061095, A038041, A057625, A038048, A005225.
%K A087905 nonn
%O A087905 1,2
%A A087905 _Vladeta Jovovic_, Oct 14 2003