MathGroup Archive 2012

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

Search the Archive

Finding a sum


I feel the sum below should have a closed form. Am I wrong? A direct attack does not work. However, by experimenting I can sum a row but I can't sum all the rows. Any ideas? Thanks.

Sum[1/(x + I y - (n + I m)), 
{n, -Infinity, Infinity}, {m, -Infinity,Infinity}]


Srow = 1/(x + I y) + 
  Sum[1/(x + I y - (n + I m)) + 1/(x + I y - (-n + I m)), 
{n, 1 , Infinity}]


Sum[Srow + (Srow /. m -> -m), {m, 1, Infinity}]



  • Prev by Date: Re: NDSolve with NIntegrate where Integral is a function of x
  • Next by Date: Re: strange booleanconvert behavior?
  • Previous by thread: Re: Options to know shape of functions
  • Next by thread: Re: Finding a sum