OFFSET
0,2
FORMULA
a(n) = Product_{k=0..floor((n-1)/2)} 2*(2*n-4*k-1). - Andrew Howroyd, Jul 10 2024
MATHEMATICA
a[0] = 1; a[n_] := a[n] = (2n)!/(n!*a[n - 1]);
Table[a[n], {n, 0, 30}]
PROG
(PARI) a(n)=prod(k=0, (n-1)\2, 2*(2*n-4*k-1)) \\ Andrew Howroyd, Jul 10 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jul 09 2024
STATUS
approved