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 A293731 #17 Oct 18 2017 05:43:10
%S A293731 1,1,9,79,937,12501,204361,3703099,76460049,1732292137,43118784361,
%T A293731 1161659388231,33771008443129,1050438417598909,34839221780655657,
%U A293731 1225699869182970931,45592202322141065761,1786608566424333658449,73553912374465725486409
%N A293731 E.g.f.: exp(Sum_{n>=1} n*A000041(n)*x^n), where A000041(n) is the number of partitions of n.
%H A293731 Seiichi Manyama, <a href="/A293731/b293731.txt">Table of n, a(n) for n = 0..410</a>
%F A293731 a(0) = 1 and a(n) = (n-1)! * Sum_{k=1..n} k^2*A000041(k)*a(n-k)/(n-k)! for n > 0.
%e A293731 a(5) = 4! * (1^2*1*a(4)/4! + 2^2*2*a(3)/3! + 3^2*3*a(2)/2! + 4^2*5*a(1)/1! + 5^2*7*a(0)/0!) = 12501.
%t A293731 nmax = 20; CoefficientList[Series[E^Sum[k*PartitionsP[k]*x^k, {k, 1, nmax}], {x, 0, nmax}], x] * Range[0, nmax]! (* _Vaclav Kotesovec_, Oct 18 2017 *)
%Y A293731 Cf. A058892, A215915.
%Y A293731 Cf. A000041.
%K A293731 nonn
%O A293731 0,3
%A A293731 _Seiichi Manyama_, Oct 15 2017