Re: Trying to recursively define a double factorial

• To: mathgroup at smc.vnet.net
• Subject: [mg126534] Re: Trying to recursively define a double factorial
• From: DrMajorBob <btreat1 at austin.rr.com>
• Date: Thu, 17 May 2012 04:11:56 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201205160820.EAA23026@smc.vnet.net>

```You don't need to do it at all, since Mathematica already has Factorial2
built in.

Bobby

On Wed, 16 May 2012 03:20:52 -0500, Jorge Cantu <monsterbone at msn.com>
wrote:

> 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?
>

--
DrMajorBob at yahoo.com

```

• Prev by Date: Coefficient
• Next by Date: Re: Trying to recursively define a double factorial
• Previous by thread: Trying to recursively define a double factorial
• Next by thread: Re: Trying to recursively define a double factorial