OFFSET
1,1
COMMENTS
Discriminant = -160. See A107132 for more information.
LINKS
Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi]
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
FORMULA
The primes are congruent to {1, 9} (mod 40). - T. D. Noe, Apr 29 2008
MATHEMATICA
QuadPrimes2[1, 0, 40, 10000] (* see A106856 *)
PROG
(Magma) [ p: p in PrimesUpTo(3000) | p mod 40 in {1, 9} ]; // Vincenzo Librandi, Jul 24 2012
(PARI) list(lim)=my(v=List(), t); forprime(p=41, lim, t=p%40; if(t==1||t==9, listput(v, p))); Vec(v) \\ Charles R Greathouse IV, Feb 09 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
T. D. Noe, May 13 2005
STATUS
approved