OFFSET
1,1
COMMENTS
Also primes of the form 2*x^2+x*y-2*y^2 (as well as of the form 2*x^2+5*x*y+y^2). Discriminant = 17. Class = 1. This was originally a separate entry, submitted by Laura Caballero Fernandez, Lourdes Calvo Moguer, Maria Josefa Cano Marquez, Oscar Jesus Falcon Ganfornina and Sergio Garrido Morales (oscfalgan(AT)yahoo.es), Jun 06 2008. R. J. Mathar proved that this coincides with the present sequence, Jul 22 2008
Also, primes which are a square (mod 17) (or, (mod 34), cf. A191025). - M. F. Hasler, Jan 15 2016
REFERENCES
Z. I. Borevich and I. R. Shafarevich, Number Theory.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
D. B. Zagier, Zetafunktionen und quadratische Körper, Springer, 1981.
MATHEMATICA
Select[Prime[Range[200]], JacobiSymbol[17, #]!=-1&] (* Harvey P. Dale, Sep 20 2011 *)
PROG
(PARI) is(n)=isprime(n)&&issquare(Mod(17, n)) \\ Charles R Greathouse IV, Mar 21 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited by N. J. A. Sloane, Jul 28 2008 at the suggestion of R. J. Mathar
STATUS
approved