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 A343353 #9 Apr 12 2021 12:14:25 %S A343353 1,1,9,73,621,5229,44293,374277,3162447,26694159,225163687,1897751079, %T A343353 15983278059,134519816427,1131395821587,9509592524371,79880259426102, %U A343353 670590654977718,5626336598011078,47179486350900358,395410837699366686,3312225325409475038,27731588831310844302 %N A343353 Expansion of Product_{k>=1} 1 / (1 - x^k)^(8^(k-1)). %F A343353 a(n) ~ exp(sqrt(n/2) - 1/16 + c/8) * 2^(3*n - 7/4) / (sqrt(Pi)*n^(3/4)), where c = Sum_{j>=2} 1/(j * (8^(j-1) - 1)). - _Vaclav Kotesovec_, Apr 12 2021 %p A343353 a:= proc(n) option remember; `if`(n=0, 1, add(a(n-j)*add( %p A343353 d*8^(d-1), d=numtheory[divisors](j)), j=1..n)/n) %p A343353 end: %p A343353 seq(a(n), n=0..22); # _Alois P. Heinz_, Apr 12 2021 %t A343353 nmax = 22; CoefficientList[Series[Product[1/(1 - x^k)^(8^(k - 1)), {k, 1, nmax}], {x, 0, nmax}], x] %t A343353 a[n_] := a[n] = If[n == 0, 1, (1/n) Sum[Sum[d 8^(d - 1), {d, Divisors[k]}] a[n - k], {k, 1, n}]]; Table[a[n], {n, 0, 22}] %Y A343353 Cf. A034691, A104460, A144072, A343349, A343350, A343351, A343352, A343354, A343355. %K A343353 nonn %O A343353 0,3 %A A343353 _Ilya Gutkovskiy_, Apr 12 2021