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 A303914 #8 May 04 2018 06:45:18 %S A303914 1,2,9,55,465,5051,69265,1147287,22307905,497211049,12484203601, %T A303914 348391613615,10691846920081,357749800027465,12958472141161457, %U A303914 505088781523073326,21076091000708067585,937322034938743608556,44256147057318887809993,2210813717869831566759857,116492226446226314836976401 %N A303914 a(n) = [x^n] (1/(1 - x))*Product_{k>=1} 1/(1 - n*x^k). %H A303914 <a href="/index/Par#part">Index entries for sequences related to partitions</a> %F A303914 a(n) = [x^n] (1/(1 - x))*exp(Sum_{k>=1} n^k*x^k/(k*(1 - x^k))). %F A303914 a(n) = Sum_{j=0..n} A246935(j,n). %F A303914 a(n) ~ n^n. - _Vaclav Kotesovec_, May 04 2018 %p A303914 b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0, %p A303914 b(n, i-1, k) +`if`(i>n, 0, k*b(n-i, i, k)))) %p A303914 end: %p A303914 a:= n-> add(b(j$2, n), j=0..n): %p A303914 seq(a(n), n=0..20); # _Alois P. Heinz_, May 02 2018 %t A303914 Table[SeriesCoefficient[1/(1 - x) Product[1/(1 - n x^k), {k, 1, n}], {x, 0, n}], {n, 0, 20}] %t A303914 Table[SeriesCoefficient[1/(1 - x) Exp[Sum[n^k x^k/(k (1 - x^k)), {k, 1, n}]], {x, 0, n}], {n, 0, 20}] %Y A303914 Cf. A000070, A124577, A246935, A303070. %K A303914 nonn %O A303914 0,2 %A A303914 _Ilya Gutkovskiy_, May 02 2018