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 A265951 #11 Aug 23 2019 20:48:30 %S A265951 1,2,8,22,68,170,484,1166,3048,7274,18000,41806,100684,229258,535692, %T A265951 1206230,2758944,6123650,13798088,30284894,67272756,146426002, %U A265951 321513284,693944814,1510245960,3236648578,6985572672,14885926182,31904642348,67618415690 %N A265951 Expansion of Product_{k>=1} 1/(1 - 2*k*x^k). %H A265951 Vaclav Kotesovec, <a href="/A265951/b265951.txt">Table of n, a(n) for n = 0..3280</a> %F A265951 a(n) ~ c * n * 2^n, where c = 1/2 * Product_{m>=3} 1/(1 - m/2^(m-1)) = 9.281573281805057363737677116134642024212942973614535341005126953773818... %p A265951 b:= proc(n, i) option remember; `if`(n=0 or i=1, %p A265951 2^n, b(n, i-1) +i*2*b(n-i, min(n-i, i))) %p A265951 end: %p A265951 a:= n-> b(n$2): %p A265951 seq(a(n), n=0..32); # _Alois P. Heinz_, Aug 23 2019 %t A265951 nmax=40; CoefficientList[Series[Product[1/(1-2*k*x^k), {k, 1, nmax}], {x, 0, nmax}], x] %Y A265951 Cf. A006906, A265974, A265975, A265976. %Y A265951 Cf. A032309, A070933, A265955. %K A265951 nonn %O A265951 0,2 %A A265951 _Vaclav Kotesovec_, Dec 19 2015