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Re: Question

  • To: mathgroup at smc.vnet.net
  • Subject: [mg9432] Re: [mg9390] Question
  • From: Robert Pratt <rpratt at math.unc.edu>
  • Date: Wed, 5 Nov 1997 01:56:46 -0500
  • Sender: owner-wri-mathgroup at wolfram.com

You need more initial conditions.  In order to use your recurrence
relation, you need to specify a[0], a[1], a[2], and a[3] (not just a[0]
and a[1]).  To see why you need to do this, first try computing a[2],
a[3], a[4] and a[5] by hand.

Rob Pratt
Department of Mathematics
The University of North Carolina at Chapel Hill CB# 3250, 331 Phillips
Hall
Chapel Hill, NC  27599-3250

rpratt at math.unc.edu

http://www.math.unc.edu/Grads/rpratt/

On Sun, 2 Nov 1997, Boguslaw Ptaszynski wrote:

> Hello Mathematica (v.3,0 for Windows) Users,
> 	I have a question that I hope someone has an answer for. I have the
> following recurrence relation:
> 
> 	a[n+2]= 1/(b^2)  ( b/2  a[n] + n (n-1)/4  a[n-2]  )
> 
> for the indices in the series n>=2.
> I want to use the formula to determine the values of a[n] for
> n=2,3,4,...12  and give these values in the table
> 
> I have written :
> 
> Clear [a,n,b]
> a[n_] := a[n]= 1/(b^2) ( b/2 a[n-2] + (n-2) (n-3)/4  a[n-4] ); a[0]=a0;
> a[1]=a1;
> TableForm[ Table[{n, a[n]}, {n,0,12}]]
> 
> an I have got the following message:
> 
> $RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
> $RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
> $RecursionLimit::"reclim": "Recursion depth of \!\(256\) exceeded."
> General::"stop": 
>     "Further output of \!\($RecursionLimit :: \"reclim\"\) will be
> suppressed \
> during this calculation."
> 
> What does the message mean? I will be happy to get any information
> abaout this problem.
> 
> 		Boguslaw Ptaszynski
> 
> 



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