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%I #11 Jul 25 2023 07:15:05
%S 1,1,15,533,36415,4624621,1108685495,513716588981,467874135168079,
%T 845152554936920445,3041003426951554000167,21840734269889733272106629,
%U 313415404907854466274076819391,8990640466019774671530066108827853
%N G.f. satisfies A(x) = 1/(1 - x*A(2x)^7).
%H Seiichi Manyama, <a href="/A171197/b171197.txt">Table of n, a(n) for n = 0..79</a>
%F a(n) ~ c * 2^(n*(n-1)/2) * 7^n, where c = 0.307176924551399606223470587229647816147018... - _Vaclav Kotesovec_, Nov 03 2021
%t nmax = 15; A[_] = 0; Do[A[x_] = 1/(1 - x*A[2*x]^7) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] (* _Vaclav Kotesovec_, Nov 03 2021 *)
%o (PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=1/(1-x*subst(A, x, 2*x)^7) ); polcoeff(A, n)}
%Y Cf. A015083, A171192-A171196, A171198.
%K nonn
%O 0,3
%A _Paul D. Hanna_, Dec 05 2009
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