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 A327124 #12 Sep 16 2019 08:51:55
%S A327124 1,-2,3,-3,5,-3,7,-2,10,0,11,-1,13,7,25,13,17,-2,19,30,56,33,23,1,26,
%T A327124 52,111,98,29,-51,31,158,198,102,56,24,37,133,325,304,41,-189,43,517,
%U A327124 626,207,47,191,50,-2,731,988,53,-435,517,1315,1026,348,59,18
%N A327124 Expansion of Sum_{k>=1} ((1 - (-x)^k)^k - 1).
%H A327124 Seiichi Manyama, <a href="/A327124/b327124.txt">Table of n, a(n) for n = 1..10000</a>
%F A327124 a(n) = Sum_{d|n} (-1)^(n-d) * binomial(n/d,d).
%F A327124 a(p) = p, where p is odd prime.
%t A327124 nmax = 60; CoefficientList[Series[Sum[((1 - (-x)^k)^k - 1), {k, 1, nmax}], {x, 0, nmax}], x] // Rest
%t A327124 Table[DivisorSum[n, (-1)^(n - #) Binomial[n/#, #] &], {n, 1, 60}]
%o A327124 (PARI) a(n)={sumdiv(n, d, (-1)^(n-d) * binomial(n/d,d))} \\ _Andrew Howroyd_, Sep 14 2019
%Y A327124 Cf. A056045, A112329, A318636, A327238.
%K A327124 sign
%O A327124 1,2
%A A327124 _Ilya Gutkovskiy_, Sep 14 2019