A208653 a(n) = Product_{i=floor((n + 1)/2)..n-1} binomial(n-1, i).

1, 1, 1, 3, 4, 50, 90, 5145, 12544, 3429216, 11340000, 15219319500, 68309049600, 457937132487120, 2790771598030416, 94609025993497640625, 783056974947287040000, 135476575389769051389952000, 1523136299736565293430210560, 1354434926051634531310373234715648

Offset

1,4

Comments

Used with A208652 to count palindromic paths for A208654.

Links

Table of n, a(n) for n=1..20.

Mathematica

m[n_]:=Floor[(n+1)/2]; z=21;
h[n_]:=Product[Binomial[n-1, i], {i, m[n], n-1}]
Table[h[n], {n, 1, z}] (* A208653 *)

Crossrefs

Cf. A208652, A208654.

Sequence in context: A198051 A032839 A056855 * A080073 A032840 A114694

Adjacent sequences: A208650 A208651 A208652 * A208654 A208655 A208656

Keyword

nonn

Author

Clark Kimberling, Mar 02 2012

Extensions

Definition corrected by Georg Fischer, Feb 01 2022

Status

approved