A137983 G.f.: A(x) = 1/(1 - x*A_0(x)) where A_0(x) = 1/(1 - 2x*A_1(x)^(1/2)) such that A_{n-1}(x) = 1/(1 - 2^n*x*[A_{n}(x)]^(1/2^n)) for n>=1 with A_0(x) equal to the g.f. of A137984.

1, 1, 3, 13, 71, 469, 3723, 36005, 436547, 6899269, 148118063, 4468393661, 193343082863, 12098043923845, 1095808155971903, 143385496616202557, 27027137980334917335, 7318231233568088061141, 2839533242388092176367563

Offset

0,3

Links

Table of n, a(n) for n=0..18.

Example

See examples given in A137984.

Prog

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

Crossrefs

Cf. A137984.

Sequence in context: A000261 A111140 A302699 * A327677 A307005 A059032

Adjacent sequences: A137980 A137981 A137982 * A137984 A137985 A137986

Keyword

nonn

Author

Paul D. Hanna, Feb 27 2008

Status

approved