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 A137962 #10 Mar 03 2018 13:53:00
%S A137962 1,1,3,18,106,720,5085,37493,284331,2204973,17404720,139369905,
%T A137962 1129411314,9244823986,76326154857,634847759955,5314684735045,
%U A137962 44746683774474,378652035541761,3218705637379698,27471657413667780
%N A137962 G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^5)^3.
%H A137962 Vaclav Kotesovec, <a href="/A137962/b137962.txt">Table of n, a(n) for n = 0..350</a>
%F A137962 G.f.: A(x) = 1 + x*B(x)^3 where B(x) is the g.f. of A137963.
%F A137962 a(n) = Sum_{k=0..n-1} C(3*(n-k),k)/(n-k) * C(5*k,n-k-1) for n>0 with a(0)=1. - _Paul D. Hanna_, Jun 16 2009
%F A137962 a(n) ~ sqrt(3*s*(1-s)*(5-6*s) / ((140*s - 120)*Pi)) / (n^(3/2) * r^n), where r = 0.1085884782751570249717333800652227343328635496829... and s = 1.301018963559115613510052458264916439485131890857... are real roots of the system of equations s = 1 + r*(1 + r*s^5)^3, 15 * r^2 * s^4 * (1 + r*s^5)^2 = 1. - _Vaclav Kotesovec_, Nov 22 2017
%o A137962 (PARI) {a(n)=local(A=1+x*O(x^n));for(i=0,n,A=1+x*(1+x*A^5)^3);polcoeff(A,n)}
%o A137962 (PARI) a(n)=if(n==0,1,sum(k=0,n-1,binomial(3*(n-k),k)/(n-k)*binomial(5*k,n-k-1))) \\ _Paul D. Hanna_, Jun 16 2009
%Y A137962 Cf. A137963, A137961; A137953, A137957, A137969.
%K A137962 nonn
%O A137962 0,3
%A A137962 _Paul D. Hanna_, Feb 26 2008