Re: Processing lists of unrelated numbers with Do or While statement

*To*: mathgroup at smc.vnet.net*Subject*: [mg39198] Re: Processing lists of unrelated numbers with Do or While statement*From*: "Diana" <diana53xiii at earthlink.remove13.net>*Date*: Mon, 3 Feb 2003 01:10:05 -0500 (EST)*References*: <b1idal$bja$1@smc.vnet.net>*Reply-to*: "Diana" <diana53xiii at earthlink.remove13.net>*Sender*: owner-wri-mathgroup at wolfram.com

Bob, Thanks for getting back to me. When I type in your code: (PrimePi[2#]-PrimePi[#]&) /@ x {1, 1, 1, 2, 3, 5, 9, 15, 28, 49, 90, 163, 302, 456} I get: {2 x, 3 x, 5 x, 7 x, 13 x, 23 x, 43 x, 83 x, 163 x, 317 x, 631 x, 1259 x, 2503 x, 4001 x} Have I mis-applied your code? Thanks, Diana "Diana" <diana53xiii at earthlink.remove13.net> wrote in message news:b1idal$bja$1 at smc.vnet.net... > Folks, > > I had a problem recently where I tried to determing the PrimePi value of 2 > times a number minus that number. This is verifying the Bertrand's > Postulate: > > PrimePi(2x) - PrimePi(x) >=1 for all x >=2, elements of Z. > > Well, > > I finally came up with: > PrimePi[2*{2, 3, 5, 7, 13, 23, 43, 83, 163, 317, 631, 1259, 2503, 4001} - > {2, 3, 5, 7, > 13, 23, 43, 83, 163, 317, 631, 1259, 2503, 4001}] > > gives: > {1, 2, 3, 4, 6, 9, 14, 23, 38, 66, 115, 205, 368, 551} > the desired answer. > Is there a way to process unrelated numbers with a Do or While or NestWhile > statement? > Thanks, > Diana > > -- > ===================================================== > "God made the integers, all else is the work of man." > L. Kronecker, Jahresber. DMV 2, S. 19. > > >