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 A289639 #25 Jul 11 2017 08:46:33
%S A289639 264,340560,141251616,85062410400,43377095394864,23729517350865216,
%T A289639 12591243615814264896,6769208775901467246912,
%U A289639 3618692733697667332476264,1939201752717876551124987360,1038098212042387655796115897440
%N A289639 Coefficients in expansion of -q*E'_10/E_10 where E_10 is the Eisenstein Series (A013974).
%H A289639 Seiichi Manyama, <a href="/A289639/b289639.txt">Table of n, a(n) for n = 1..366</a>
%F A289639 a(n) = Sum_{d|n} d * A289024(d).
%F A289639 a(n) = A288261(n)/3 + A288840(n)/2 + 20*A000203(n).
%F A289639 a(n) = -Sum_{k=1..n-1} A013974(k)*a(n-k) - A013974(n)*n.
%F A289639 G.f.: 1/3 * E_6/E_4 + 1/2 * E_8/E_6 - 5/6 * E_2.
%F A289639 a(n) ~ exp(2*Pi*n). - _Vaclav Kotesovec_, Jul 09 2017
%t A289639 nmax = 20; Rest[CoefficientList[Series[264*x*Sum[k*DivisorSigma[9, k]*x^(k-1), {k, 1, nmax}]/(1 - 264*Sum[DivisorSigma[9, k]*x^k, {k, 1, nmax}]), {x, 0, nmax}], x]] (* _Vaclav Kotesovec_, Jul 09 2017 *)
%Y A289639 -q*E'_k/E_k: A289635 (k=2), A289636 (k=4), A289637 (k=6), A289638 (k=8), this sequence (k=10), A289640 (k=14).
%Y A289639 Cf. A006352 (E_2), A013974 (E_10), A285836, A289024.
%K A289639 nonn
%O A289639 1,1
%A A289639 _Seiichi Manyama_, Jul 09 2017