A071755 Expansion of (1+x^4*C^4)*C^2, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.

1, 2, 5, 14, 43, 138, 456, 1540, 5291, 18434, 64974, 231268, 830110, 3001316, 10920630, 39959280, 146943435, 542771250, 2012905950, 7492104180, 27977841930, 104792420460, 393587773800, 1482017530968, 5593455054558

Offset

0,2

Links

Table of n, a(n) for n=0..24.

Mathematica

CoefficientList[Series[(1+x^4((1-Sqrt[1-4x])/(2x))^4)((1-Sqrt[1-4x])/ (2x))^2, {x, 0, 25}], x] (* Harvey P. Dale, Jul 26 2011 *)

Crossrefs

Sequence in context: A071747 A071751 A052301 * A149879 A366025 A366042

Adjacent sequences: A071752 A071753 A071754 * A071756 A071757 A071758

Keyword

nonn

Author

N. J. A. Sloane, Jun 06 2002

Status

approved