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 A308154 #12 May 15 2019 06:21:05 %S A308154 1,1,2,5,11,26,64,159,397,1042,2701,7249,19341,52927,143615,399359, %T A308154 1099846,3087498,8616361,24386458,68617936,195678409,554862501, %U A308154 1590363317,4539073167,13071768304,37496646028,108449257539,312439316258,906653694239,2622887257356 %N A308154 G.f.: x * Product_{j>=1, k>=1} (1 + a(j)*x^(j*k)). %p A308154 A:= proc(n) option remember; series(x*`if`(n=1, 1, mul(mul( %p A308154 1+a(j)*x^(j*k), k=1..(n-1)/j), j=1..n-1)), x, n+1) %p A308154 end: %p A308154 a:= n-> coeff(A(n), x, n): %p A308154 seq(a(n), n=1..35); # _Alois P. Heinz_, May 14 2019 %t A308154 a[n_] := a[n] = SeriesCoefficient[x Product[Product[(1 + a[j] x^(j k)), {k, 1, n - 1}], {j, 1, n - 1}], {x, 0, n}]; Table[a[n], {n, 1, 32}] %Y A308154 Cf. A032305, A308060, A308153. %K A308154 nonn %O A308154 1,3 %A A308154 _Ilya Gutkovskiy_, May 14 2019