(re 2nd question below) Well, for negative N, the expression 1 + 2^2^N is always a unit, never a prime or composite. For N>=0, it seems to be prime 5 times, and likely composite ever after. Rich -----Original Message----- From: math-fun-bounces+rschroe=sandia.gov@mailman.xmission.com on behalf of dasimov@earthlink.net Sent: Mon 6/26/2006 1:18 PM To: math-fun Subject: RE: [math-fun] Prime Generating Polynomials Rich wrote: << More sophisticated challenge: Find a formula whose prime likelihood is something different from Constant * 1/logN. . . .
Is it known whether there is a polynomial of degree >= 2 whose asymptotic proportion of primes at integer arguments is the same as for the polynomial P(x) = x ? Also: If negative primes count just as positive primes do, then could using only positive integer arguments give a different result from using only negative integer arguments ? --Dan _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun