A171194 G.f. satisfies A(x) = 1/(1 - x*A(2x)^4).

1, 1, 9, 185, 7241, 525513, 71973193, 19054326985, 9916177373001, 10235479554015689, 21045100094428458057, 86370025530284981044937, 708236082282948046820221257, 11609413456993946896013575994313

Offset

0,3

Links

Seiichi Manyama, Table of n, a(n) for n = 0..80

Formula

a(n) ~ c * 2^(n*(n+3)/2), where c = 0.5726679317239416602436569686037310143000778... - Vaclav Kotesovec, Nov 03 2021

Mathematica

nmax = 15; A[_] = 0; Do[A[x_] = 1/(1 - x*A[2*x]^4) + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x] (* Vaclav Kotesovec, Nov 03 2021 *)

Prog

(PARI) {a(n)=local(A=1+x+x*O(x^n)); for(i=0, n, A=1/(1-x*subst(A, x, 2*x)^4) ); polcoeff(A, n)}

Crossrefs

Cf. A015083, A171192, A171193, A171195-A171198.

Sequence in context: A300598 A189803 A216409 * A196297 A274781 A293848

Adjacent sequences: A171191 A171192 A171193 * A171195 A171196 A171197

Keyword

nonn

Author

Paul D. Hanna, Dec 05 2009

Status

approved