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 A258799 #5 Jun 11 2015 06:23:49
%S A258799 1,1,3,13,61,324,1800,10340,60969,366486,2237120,13829487,86394782,
%T A258799 544547651,3458637273,22113504345,142212705879,919294844898,
%U A258799 5969839457411,38927450022860,254776529381625,1673102335692514,11020847332241873,72798664086854460
%N A258799 a(n) = [x^n] Product_{k=1..n} (1+x^k)^3 / x^(2*k).
%F A258799 a(n) ~ c * d^n / n^(3/2), where d = 7.036711302278424796297167109247361745558645910729132828752853658917..., c = 0.282321145891... .
%t A258799 Table[SeriesCoefficient[Product[(1+x^k)^3/x^(2*k), {k, 1, n}], {x, 0, n}], {n, 0, 30}]
%t A258799 Table[SeriesCoefficient[Product[1+x^k, {k, 1, n}]^3, {x, 0, n*(n+2)}], {n, 0, 30}]
%t A258799 (* A program to compute the constant d *) (1+r)^3/r /.FindRoot[Log[1+r]/Log[r] + (PolyLog[2,-r] + Pi^2/12) / Log[r]^2 == 1/6, {r, E}, WorkingPrecision->100]
%Y A258799 Cf. A258797, A258798.
%K A258799 nonn
%O A258799 0,3
%A A258799 _Vaclav Kotesovec_, Jun 10 2015