OFFSET
1,1
COMMENTS
Let d be any divisors of 1000, then d and -d are quadratic residues modulo these primes. All terms are of the form x^2 - d*y^2 for d = -40, -25, -10, -8, -5, -4, -2, -1, 2, 5, 8, 10. Conjecture: they are also of the form x^2 - d*y^2 for d = 20, 40, 50, 200. - Jianing Song, Aug 29 2018
PROG
(PARI) for(k=0, 130, if(isprime(1000*k+1), print1(1000*k+1, ", "))) \\ Jianing Song, Aug 29 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Avik Roy (avik_3.1416(AT)yahoo.co.in), Feb 12 2009
EXTENSIONS
More terms from R. J. Mathar, Feb 19 2009
STATUS
approved