FactorialPower

FactorialPower[x, n] gives the falling factorial x(x-1)(x-2)...(x-n+1).

FactorialPower[x, n, h] gives the step-h factorial power.

Examples

Falling factorial:

FactorialPower[5, 3]
(* 60 - equals 5×4×3 *)

With step parameter:

FactorialPower[x, 3, 2]
(* x(x-2)(x-4) *)

Please visit the official Wolfram Language Reference for more details.