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 A076717 #14 Mar 24 2021 08:47:32
%S A076717 1,1,4,-1,6,4,8,-25,37,16,12,-106,14,92,384,-561,18,-65,20,-706,2552,
%T A076717 1948,24,-15658,3151,8048,20440,-2570,30,-33326,32,-135393,178512,
%U A076717 130816,94968,-583219,38,523964,1596560,-2465370,42,-2521186,44,-15082,16364502,8388124,48,-78560082,823593,23888231
%N A076717 a(n) = -Sum_{d|n} (-n/d)^d.
%H A076717 Seiichi Manyama, <a href="/A076717/b076717.txt">Table of n, a(n) for n = 1..5000</a>
%F A076717 G.f.: Sum_{n>0} n*x^n/(1+n*x^n).
%o A076717 (PARI) a(n) = -sumdiv(n, d, (-n/d)^d); \\ _Michel Marcus_, Mar 22 2021
%Y A076717 Cf. A055225, A308367, A321438.
%K A076717 sign
%O A076717 1,3
%A A076717 _Vladeta Jovovic_, Oct 27 2002