

A093113


Coefficients of the solution to a functional equation.


0



1, 2, 6, 16, 62, 192, 652, 2048, 9270, 31744, 116948, 393216, 1533868, 5341184, 19445016, 67108864, 332958758, 1215037440, 4711687300, 16642998272, 67697833092, 245257732096, 923984441000, 3298534883328, 13952454631996
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

G.f. A(x) satisfies A(4x^2)=A(x)+A(x)=4A(x)A(x). Also A(4x^2)=4A(x)^2/(1+4A(x)).


LINKS

Table of n, a(n) for n=1..25.


PROG

(PARI) a(n)=local(A, m); if(n<1, 0, A=x+O(x^2); m=1; while(m<=n, m*=2; A=subst(A, x, x^2); A=A/2+sqrt(A^2/4+A)); polcoeff(A, n)*4^(n1))


CROSSREFS

Sequence in context: A324062 A033301 A197102 * A150030 A150031 A121753
Adjacent sequences: A093110 A093111 A093112 * A093114 A093115 A093116


KEYWORD

nonn


AUTHOR

Michael Somos, Mar 20 2004


STATUS

approved



