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 A171198 #19 Jul 06 2025 10:39:53
%S A171198 1,1,17,689,53777,7805201,2138582801,1132509669905,1178804946216209,
%T A171198 2433551908785577745,10007244528797884954897,
%U A171198 82140401194398306308608785,1347106337625031145913841134865,44163564651481078406730693648713489
%N A171198 G.f. A(x) satisfies A(x) = 1/(1 - x*A(2*x)^8).
%H A171198 Seiichi Manyama, <a href="/A171198/b171198.txt">Table of n, a(n) for n = 0..79</a>
%F A171198 a(n) ~ c * 2^(n*(n+5)/2), where c = 0.265929653305627916979803234586945454418485... - _Vaclav Kotesovec_, Nov 03 2021
%F A171198 a(0) = 1; a(n) = 2^(n-1) * Sum_{x_1, x_2, ..., x_9>=0 and x_1+x_2+...+x_9=n-1} (1/2)^x_1 * Product_{k=1..9} a(x_k). - _Seiichi Manyama_, Jul 06 2025
%t A171198 nmax = 15; A[_] = 0; Do[A[x_] = 1/(1 - x*A[2*x]^8) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] (* _Vaclav Kotesovec_, Nov 03 2021 *)
%o A171198 (PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=1/(1-x*subst(A, x, 2*x)^8) ); polcoeff(A, n)}
%Y A171198 Cf. A015083, A171192-A171197.
%K A171198 nonn
%O A171198 0,3
%A A171198 _Paul D. Hanna_, Dec 05 2009