Re: Summations with Primes

*To*: mathgroup at smc.vnet.net*Subject*: [mg39958] Re: Summations with Primes*From*: Friedrich Laher <mathefritz at schmieder-laher.de>*Date*: Thu, 13 Mar 2003 03:02:27 -0500 (EST)*References*: <b4mnus$imf$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

use wrapper ff[i_]:=If[PrimeQ[i],f[i],0] and do the summation with ff instead of f or take the If direktly as the expression to Sum, e.g. Sum[If[PrimeQ[i],i,0],{i,0,20}] 77 Anthony Felder schrieb: > 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 > >