OFFSET
1,1
COMMENTS
All prime divisors of 3+4Q^2 are congruent to 1 modulo 6.
At least one prime divisor of 3+4Q^2 is congruent to 3 modulo 4 and hence to 7 modulo 12.
The first six terms are the same as those of A057204.
LINKS
Tyler Busby, Table of n, a(n) for n = 1..21
EXAMPLE
a(3) = 1482549740515442455520791 is the smallest prime divisor congruent to 7 mod 12 of 3+4Q^2 = 5281642303363312989311974746340327 = 3562539697 * 1482549740515442455520791, where Q = 7 * 199 * 7761799 * 487 * 67 * 103.
MATHEMATICA
a={7}; q=1;
For[n=2, n<=7, n++,
q=q*Last[a];
AppendTo[a, Min[Select[FactorInteger[4*q^2+3][[All, 1]], Mod[#, 12]==7 &]]];
];
a (* Robert Price, Jul 15 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Nick Hobson, Nov 18 2006
STATUS
approved