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 A022615 #13 Apr 05 2017 11:26:15
%S A022615 1,-20,190,-1160,5245,-19324,62150,-182040,495750,-1269620,3088376,
%T A022615 -7197240,16164595,-35136760,74192590,-152674048,306968470,-604298520,
%U A022615 1166898210,-2213813640,4132159452,-7597272900
%N A022615 Expansion of Product_{m>=1} (1+q^m)^(-20).
%H A022615 Seiichi Manyama, <a href="/A022615/b022615.txt">Table of n, a(n) for n = 0..10000</a>
%F A022615 a(n) ~ (-1)^n * 5^(1/4) * exp(Pi*sqrt(10*n/3)) / (2 * 6^(1/4) * n^(3/4)). - _Vaclav Kotesovec_, Aug 27 2015
%F A022615 a(0) = 1, a(n) = -(20/n)*Sum_{k=1..n} A000593(k)*a(n-k) for n > 0. - _Seiichi Manyama_, Apr 05 2017
%t A022615 nmax = 50; CoefficientList[Series[Product[1/(1 + x^k)^20, {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Aug 27 2015 *)
%K A022615 sign
%O A022615 0,2
%A A022615 _N. J. A. Sloane_