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A138216 G.f.: A(x) = 1 + x*(1 + x*(1 + x*(...(1 + x*(...)^(6n))...)^18)^12)^6.

%I A138216 #2 Mar 30 2012 18:37:09
%S A138216 1,1,6,87,2072,69051,2960496,155190175,9614870340,687262107456,
%T A138216 55663739264928,5037617218937667,503778146624222544,
%U A138216 55164755650126969274,6564517420892162939514,843494176565238712267131
%N A138216 G.f.: A(x) = 1 + x*(1 + x*(1 + x*(...(1 + x*(...)^(6n))...)^18)^12)^6.
%e A138216 G.f.: A(x)=1+x*B(x)^6, B(x)=1+x*C(x)^12, C(x)=1+x*D(x)^18, D(x)=1+x*E(x)^24,...
%e A138216 where A(x),B(x),C(x),... are the g.f. of the sequences given below.
%e A138216 A=[1,1,6,87,2072,69051,2960496,155190175,9614870340,...];
%e A138216 B=[1,1,12,282,9616,424035,22794444,1441538178,104721633324,...];
%e A138216 C=[1,1,18,585,26088,1443708,94316940,7064386296,595172880432,...];
%e A138216 D=[1,1,24,996,54944,3668826,283322664,24650121400,2376215009736,...];
%e A138216 E=[1,1,30,1515,99640,7802145,696663576,69221991825,7536986249580,...];
%e A138216 F=[1,1,36,2142,163632,14708421,1492326612,166960071642,...]; ...
%o A138216 (PARI) {a(n)=local(A=1+x+x*O(x^n)); for(j=0, n-1, A=1+x*A^(6*(n-j))); polcoeff(A, n)}
%Y A138216 Cf. A095793, A138211, A138212, A138213, A138214, A138215.
%K A138216 nonn
%O A138216 0,3
%A A138216 _Paul D. Hanna_, Mar 06 2008