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 A319509 #10 Oct 12 2018 03:05:22
%S A319509 1,-1,13,-828,145046,-53306325,35351663831,-38335940184976,
%T A319509 63385171527442332,-151639317344211911505,503956292395339783686325,
%U A319509 -2252032996384696958326480356,13175456854397460097168816336930,-98695402553214372025148083384255381
%N A319509 a(n) = n! * [x^n] 1/(1 - n + exp(x)*(exp(n*x) - 1)/(exp(x) - 1)).
%H A319509 G. C. Greubel, <a href="/A319509/b319509.txt">Table of n, a(n) for n = 0..167</a>
%F A319509 a(n) = n! * [x^n] 1/(1 - n + exp(x) + exp(2*x) + exp(3*x) + ... + exp(n*x)).
%t A319509 Table[n! SeriesCoefficient[1/(1 - n + Exp[x] (Exp[n x] - 1)/(Exp[x] - 1)), {x, 0, n}], {n, 0, 13}]
%o A319509 (PARI) default(seriesprecision, 101); {a(n) = n!*polcoeff((1/(1-n+exp(x)*(exp(n*x)-1)/(exp(x)-1)) + O(x^(n+1))), n)};
%o A319509 for(n=0, 25, print1(a(n), ", ")) \\ _G. C. Greubel_, Oct 09 2018
%Y A319509 Cf. A319508.
%K A319509 sign
%O A319509 0,3
%A A319509 _Ilya Gutkovskiy_, Sep 21 2018