Re: Summation question
- To: mathgroup at smc.vnet.net
- Subject: [mg85700] Re: Summation question
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Tue, 19 Feb 2008 07:04:15 -0500 (EST)
- Organization: Uni Leipzig
- References: <fpdu7v$qlq$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi,
Sum[f[i], {i, {1, 3, 5, 7, 11, 13}}]
or
Sum[Piecewise[{{f[i], PrimeQ[i]}}], {i, 1, 14}]
??
Regards
Jens
Robert Pigeon wrote:
> Good day all,
>
> I want to make a summation like this: Sum[f[i],{i, start,
> finish}]. What I want is that the sum be over a specific set like
> {1,3,5,7,11,13}. So the sum would be : f[1]+f[3]+f[5]+f[7]+f[11]+f[13]. The
> set I want to use is the primes. So, how do I use, if possible, Sum over a
> specific set ?
>
>
>
> Thanks,
>
>
>
> Robert
>
>
>
> Robert Pigeon
>
>