OFFSET
1,1
EXAMPLE
a(2) = 17: y = x^2+5x+17.
If x = 0; y = 0+0+17 = 17, which is prime.
If x = 1; y = 1+5+17 = 23, which is prime.
If x = 2; y = 4+10+17 = 31, which is prime.
If x = 3; y = 9+15+17 = 41, which is prime.
PROG
(PARI) isok(n) = {for (x=0, 3, if (! isprime(x^2+5*x+n), return (0)); ); return (1); } \\ Michel Marcus, Aug 09 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Ray G. Opao, Aug 22 2004
STATUS
approved