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 A022680 #9 Sep 08 2022 08:44:46 %S A022680 1,-20,150,-400,-875,7396,-7770,-36600,56510,154660,-872,-1314200, %T A022680 -455605,6284960,3781830,-9954864,-43558410,-16664680,165132890, %U A022680 229738040,57372644,-1326447180,-2095012310,1723402120,7805180205 %N A022680 Expansion of Product_{m>=1} (1-m*q^m)^20. %H A022680 G. C. Greubel, <a href="/A022680/b022680.txt">Table of n, a(n) for n = 0..1000</a> %t A022680 With[{nmax = 50}, CoefficientList[Series[Product[(1 - k*q^k)^20, {k, 1, nmax}], {q, 0, nmax}], q]] (* _G. C. Greubel_, Jul 18 2018 *) %o A022680 (PARI) m=50; q='q+O('q^m); Vec(prod(n=1,m,(1-n*q^n)^20)) \\ _G. C. Greubel_, Jul 18 2018 %o A022680 (Magma) Coefficients(&*[(1-m*x^m)^20:m in [1..40]])[1..40] where x is PolynomialRing(Integers()).1; // _G. C. Greubel_, Jul 18 2018 %K A022680 sign %O A022680 0,2 %A A022680 _N. J. A. Sloane_