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 A010840 #20 Aug 13 2023 08:47:41
%S A010840 1,-40,740,-8320,62530,-322048,1085240,-1799680,-2821065,26012480,
%T A010840 -66837420,35093760,268749870,-783902720,526221400,1691816960,
%U A010840 -3960854625,1042577120,5103133240,-380798080,-10159511430
%N A010840 Expansion of Product_{k>=1} (1-x^k)^40.
%D A010840 Newman, Morris; A table of the coefficients of the powers of eta(tau). Nederl. Akad. Wetensch. Proc. Ser. A. 59 = Indag. Math. 18 (1956), 204-216.
%H A010840 Seiichi Manyama, <a href="/A010840/b010840.txt">Table of n, a(n) for n = 0..10000</a>
%H A010840 M. Boylan, <a href="http://dx.doi.org/10.1016/S0022-314X(02)00037-9">Exceptional congruences for the coefficients of certain eta-product newforms</a>, J. Number Theory 98 (2003), no. 2, 377-389.
%H A010840 <a href="/index/Pro#1mxtok">Index entries for expansions of Product_{k >= 1} (1-x^k)^m</a>
%F A010840 a(0) = 1, a(n) = -(40/n) * Sum_{k=1..n} A000203(k)*a(n-k) for n > 0. - _Seiichi Manyama_, Aug 13 2023
%Y A010840 Column k=40 of A286354.
%Y A010840 Cf. A000203.
%K A010840 sign
%O A010840 0,2
%A A010840 _N. J. A. Sloane_