RE: Summations with Primes

*To*: mathgroup at smc.vnet.net*Subject*: [mg39978] RE: [mg39932] Summations with Primes*From*: "Harvey P. Dale" <hpd1 at nyu.edu>*Date*: Thu, 13 Mar 2003 03:04:50 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

Anthony: It's not clear to me whether you wish i to be the index of the prime number, or merely an integer. If you wish the former, this should do it (assuming i goes from 30 to 70, for example): Sum[Prime[i],{i,30,70}] If you wish the latter, this should do it (assuming i goes from 30 to 70, for example: Plus@@Select[Range[30,70],PrimeQ] but if the range is large, e.g., from 30 to 7000, the following might be faster: Plus@@Prime[Range[PrimePi[30]+1,PrimePi[7000]]] Best, Harvey Harvey P. Dale University Professor of Philanthropy and the Law Director, National Center on Philanthropy and the Law New York University School of Law Room 206A 110 West 3rd Street New York, N.Y. 10012-1074 -----Original Message----- From: Anthony Felder [mailto:afelder at crsi.org] To: mathgroup at smc.vnet.net Subject: [mg39978] [mg39932] Summations with Primes Can you tell me if, when calculating a summation of f(i) where i goes from imin to imax, Mathematica can be forced to only use prime values for i? Thank you for your time Anthony Felder