%I A137974
%S A137974 1,1,6,45,410,4020,41826,452207,5033910,57300285,663912420,7804131660,
%T A137974 92838682242,1115595461915,13521340799310,165104951405235,
%U A137974 2029162664033790,25081468301798301,311593507408597920
%N A137974 G.f. satisfies A(x) = 1 + x*(1 + x*A(x)^5)^6.
%F A137974 G.f.: A(x) = 1 + x*B(x)^6 where B(x) is the g.f. of A137973.
%F A137974 a(n) = Sum_{k=0..n-1} C(6*(n-k),k)/(n-k) * C(5*k,n-k-1) for n>0 with 
               a(0)=1. [From Paul D. Hanna (pauldhanna(AT)juno.com), Jun 16 2009]
%o A137974 (PARI) {a(n)=local(A=1+x*O(x^n));for(i=0,n,A=1+x*(1+x*A^5)^6);polcoeff(A,
               n)}
%o A137974 (PARI) a(n)=if(n==0,1,sum(k=0,n-1,binomial(6*(n-k),k)/(n-k)*binomial(5*k,
               n-k-1))) [From Paul D. Hanna (pauldhanna(AT)juno.com), Jun 16 2009]
%Y A137974 Cf. A137973; A137968, A137970, A137972.
%Y A137974 Sequence in context: A025551 A101600 A135148 this_sequence A001879 A019577 
               A097814
%Y A137974 Adjacent sequences: A137971 A137972 A137973 this_sequence A137975 A137976 
               A137977
%K A137974 nonn
%O A137974 0,3
%A A137974 Paul D. Hanna (pauldhanna(AT)juno.com), Feb 26 2008