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 A318484 #9 Aug 28 2018 13:00:48 %S A318484 1,1,6,18,52,142,404,1018,2624,6645,16124,38857,92245,214841,494098, %T A318484 1125062,2522188,5604930,12327860,26838595,57913194,123951482, %U A318484 263019720,553989989,1158449522,2405179547,4961047246,10168544537,20714279168,41952595411,84494479578 %N A318484 Expansion of Product_{k>=1} (1 + k*x^k)^sigma(k), where sigma = A000203. %H A318484 Vaclav Kotesovec, <a href="/A318484/b318484.txt">Table of n, a(n) for n = 0..10000</a> %t A318484 nmax = 40; CoefficientList[Series[Product[(1+k*x^k)^DivisorSigma[1, k], {k, 1, nmax}], {x, 0, nmax}], x] %t A318484 nmax = 40; s = 1 + x; Do[s *= Sum[Binomial[DivisorSigma[1, k], j]*k^j*x^(j*k), {j, 0, nmax/k}]; s = Expand[s]; s = Take[s, Min[nmax + 1, Exponent[s, x] + 1, Length[s]]];, {k, 2, nmax}]; CoefficientList[s, x] %Y A318484 Cf. A000203, A022629, A266891, A318416, A107742, A192065, A318483. %K A318484 nonn %O A318484 0,3 %A A318484 _Vaclav Kotesovec_, Aug 27 2018