Trying to recursively define a double factorial

*To*: mathgroup at smc.vnet.net*Subject*: [mg126507] Trying to recursively define a double factorial*From*: Jorge Cantu <monsterbone at msn.com>*Date*: Wed, 16 May 2012 04:20:52 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

My goal here is to define a recursive function for a double factorial. The domain of this function is the set of positive integers. For a positive even integer n the value DF[n] is the product of all positive even integers which are <n. For a positive odd integer n the value DF[n] is the product of all positive odd integers which are <n. I wanna make a recursive function of this double factorial without If(and other similar statements). Here is my work so far: Clear[MyF1, n]; MyF1[1] = 1; MyF1[n_Integer] /; (n > 0) := MyF1[n] = n*MyF1[n - 1] Table[MyF1[k], {k, (*integer*), (*integer*)}] How do I do this?

**Follow-Ups**:**Re: Trying to recursively define a double factorial***From:*Murray Eisenberg <murray@math.umass.edu>

**Re: Trying to recursively define a double factorial***From:*Bob Hanlon <hanlonr357@gmail.com>

**Re: Trying to recursively define a double factorial***From:*James Stein <mathgroup@stein.org>

**Re: Trying to recursively define a double factorial***From:*Tomas Garza <tgarza10@msn.com>

**Re: Trying to recursively define a double factorial***From:*DrMajorBob <btreat1@austin.rr.com>