A027317 a(n) = Sum_{k=0..m-2} T(n,k) * T(n,k+2), where m=n for n=0,1,2,3; m=2n for n >= 4; and T is given by A026082.

1, 6, 71, 561, 4797, 41462, 359530, 3124752, 27213084, 237432807, 2075064759, 18162872365, 159198909233, 1397157808149, 12275908402205, 107974903916703, 950639462501475, 8377212510209165, 73882962176311701, 652114141845864819, 5759883148706408695

Offset: 2

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Oct 27 2019