OFFSET
1,1
COMMENTS
All prime divisors of (R^17 - 1)/(R - 1) different from 17 are congruent to 1 modulo 34.
REFERENCES
M. Ram Murty, Problems in Analytic Number Theory, Springer-Verlag, NY, (2001), pp. 208-209.
EXAMPLE
a(2) = 307 is the smallest prime divisor congruent to 1 mod 34 of (R^17 - 1)/(R-1) = 7813154903878257490980895975711871949096304270238017 = 307 * 326669135226428664734261 * 77907623430368753779713071, where Q = 103 and R = 17*Q.
MATHEMATICA
a={103}; q=1;
For[n=2, n<=5, n++,
q=q*Last[a]; r=17*q;
AppendTo[a, Min[Select[FactorInteger[(r^17-1)/(r-1)][[All, 1]], Mod[#, 34]==1 &]]];
];
a (* Robert Price, Jul 14 2015 *)
CROSSREFS
KEYWORD
more,nonn
AUTHOR
Nick Hobson, Nov 18 2006
EXTENSIONS
a(9)-a(14) from Sean A. Irvine, Jun 27 2011
STATUS
approved