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A hard Series problem.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg13705] A hard Series problem.
  • From: "Ersek, Ted R" <ErsekTR at navair.navy.mil>
  • Date: Wed, 19 Aug 1998 01:38:02 -0400
  • Sender: owner-wri-mathgroup at wolfram.com

Using the Limit package I was able to find the first several terms in a
Laurent series of  Log[(1-Erf[x]) x Sqrt[x]]. The terms I was able to
find are shown below.

Log[(1-Erf[x])x Sqrt[Pi]]=
	-x^2+(1/2)x^(-2)-(5/8)x^(-4)+(37/24)x^(-6)+(353/64)x^(-8)- ....

The above uses Mathematica's definition of Erf, which is:
Erf[x]=2/Sqrt[Pi] Integrate[Exp[-t^2],{t,0,x}]

I ran into a brick wall when I tried to find other terms.

I couldn't get the expression above using Series, but I was able to find
the terms one at a time by using Limit.
Any other ideas on how to determine the terms of the series?

Can anyone find some more terms of the series? A general expression for
the nth term of the series would be fabulous.

Ted Ersek


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