A126159 a(n) = Sum_{k=0..n} C(2n,k)*A126155(n,k).

1, 12, 624, 72768, 15073536, 4879690752, 2275446779904, 1444596033404928, 1198103353905709056, 1257795823373397000192, 1630379271356490615619584, 2557344389023281412086693888, 4774145871907749099664809394176

Offset

0,2

Links

Table of n, a(n) for n=0..12.

Formula

a(n) = 4^n*Sum_{k=0..n} 2^(n-k)*3^k*A088874(n,k). - Philippe Deléham, Dec 21 2006

Example

a(1) = 1*(1) + 2*(5) + 1*(1) = 12;
a(2) = 1*(7) + 4*(35) + 6*(55) + 4*(35) + 1*(7) = 624;
a(3) = 1*(139) + 6*(695) + 15*(1195) + 20*(1415) + 15*(1195) + 6*(695) + 1*(139) = 72768.

Crossrefs

Cf. A126155.

Sequence in context: A220312 A288686 A013587 * A220992 A241227 A268549

Adjacent sequences: A126156 A126157 A126158 * A126160 A126161 A126162

Keyword

nonn

Author

Paul D. Hanna, Dec 20 2006

Status

approved