Re: Trying to recursively define a double factorial

*To*: mathgroup at smc.vnet.net*Subject*: [mg126533] Re: Trying to recursively define a double factorial*From*: Tomas Garza <tgarza10 at msn.com>*Date*: Thu, 17 May 2012 04:11:35 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201205160820.EAA23026@smc.vnet.net>

I can't see where the "double" comes in. It seems to be an ordinary factorial and a Table of values for the factorial. E.g. In[15]:= Clear[MyF1, n]; MyF1[n_Integer] := n*MyF1[n - 1] /; n > 1; MyF1[1]= 1; In[16]:= Table[MyF1[k], {k, 3, 6}] Out[16]= {6, 24, 120, 720} -Tomas > Date: Wed, 16 May 2012 04:20:52 -0400 > From: monsterbone at msn.com > Subject: Trying to recursively define a double factorial > To: mathgroup at smc.vnet.net > > My goal here is to define a recursive function for a double factorial. T= he 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 integ= ers 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? >

**References**:**Trying to recursively define a double factorial***From:*Jorge Cantu <monsterbone@msn.com>