Re: Summations with Primes
- To: mathgroup at smc.vnet.net
- Subject: [mg39961] Re: [mg39932] Summations with Primes
- From: Sseziwa Mukasa <mukasa at jeol.com>
- Date: Thu, 13 Mar 2003 03:02:44 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
On Wednesday, March 12, 2003, at 02:29 AM, Anthony Felder wrote:
>
> 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
>
>
>
Two options:
This function returns the number of primes including the smallest prime
greater than or equal to n.
primeceiling[n_Integer]:=PrimePi[n]+If[PrimeQ[n],0,1]
You can use it to compute the sum as follows
Sum[f[Prime[i]],{i,
or you can simply check if i is prime
Sum[If[PrimeQ[i],f[i],0],{i,imin,imax}]
Regards,
Ssezi