Re: goldbach prime partitions for arbitrary integer n => 4
- To: mathgroup at smc.vnet.net
- Subject: [mg43012] Re: goldbach prime partitions for arbitrary integer n => 4
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Fri, 8 Aug 2003 00:26:26 -0400 (EDT)
- Organization: The University of Western Australia
- References: <bgsn4c$nnq$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <bgsn4c$nnq$1 at smc.vnet.net>, gilmar.rodriguez at nwfwmd.state.fl.us (Gilmar Rodríguez Pierluissi) wrote: > If one wishes to compute: > eqn={p+q==200}; constraints={2<=p<=100, p<=q, p,q \[Element]Primes}; > wouldn't it be nice that if you evaluate: > Solve[eqn,constraints,{p,q}] > you would get: > {{97,103},{73,127},{61,139},{43,157},{37,163},{19,181},{7,193},{3,197}} ? > A module (or program) that could solve: > eqn={p+q==n}; constraints={2<=p<=n/2, p<=q, p,q \[Element]Primes}; > Solve[eqn,constraints,{p,q}] > for a specified n, (n=>4, n \[Element]Integer), would be even better! > Thank you! Although others will probably provide more efficient (and general) solutions, here is one way to generate the solutions you are after: PrimePair[n_Integer] := Select[Table[Prime[i], {i, PrimePi[n/2]}], PrimeQ[n - #] & ] /. p_ :> {p, n - p} PrimePair[200] Cheers, Paul -- Paul Abbott Phone: +61 8 9380 2734 School of Physics, M013 Fax: +61 8 9380 1014 The University of Western Australia (CRICOS Provider No 00126G) 35 Stirling Highway Crawley WA 6009 mailto:paul at physics.uwa.edu.au AUSTRALIA http://physics.uwa.edu.au/~paul