OFFSET
2,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 2..1000
FORMULA
a(n) = (2*n-1)*(6*n*a(n-1)-8*(2*n-3)*a(n-2))/(n*(n+1)) for n>2, a(2)=2, a(n)=0 for n<2.
a(n) = (2^(n-1)-1) * binomial(2n,n)/(n+1) = (2^(n-1)-1)*A000108(n). - Vaclav Kotesovec, Jun 01 2015
MAPLE
a:= proc(n) option remember; `if`(n<3, [0$2, 2][n+1],
(2*n-1)*(6*n*a(n-1) -8*(2*n-3)*a(n-2))/(n*(n+1)))
end:
seq(a(n), n=2..25);
MATHEMATICA
Table[(2^(n-1)-1)*Binomial[2n, n]/(n+1), {n, 2, 20}] (* Vaclav Kotesovec, Jun 01 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, May 28 2015
STATUS
approved