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Re: Finding length in recursive definition?

• To: mathgroup at smc.vnet.net
• Subject: [mg60894] Re: Finding length in recursive definition?
• From: Peter Pein <petsie at dordos.net>
• Date: Sun, 2 Oct 2005 01:54:45 -0400 (EDT)
• References: <dhlcj2$d16$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Jose Reckoner wrote:
> I have something like:
> f[1] = 1
> f[2] = 3
> f[n_] := f[n] = f[n - 1] + f[n - 2]
> 
> and in the course of work, f[n] gets evaluated an unknown number of
> times resulting in
> 
> 
>>>?f
> 
> f[1] = 1
> f[2] = 3
> f[3] = 4
> f[n_] := f[n] = f[n - 1] + f[n - 2]
> 
> I want to figure out the greatest integer n such that f[n] has already
> been computed and is stored. In this case, it is 3.
> 
> How can I do this?
> 
> Thanks!
> 
> Jose
> 

Max[Cases[DownValues[f][[All,1,1,1]],_Integer]]

   3


Peter