[Date Index] [Thread Index] [Author Index]

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>