OFFSET
1,1
COMMENTS
Sequence is infinite assuming Schinzel's hypothesis H. - Charles R Greathouse IV, Dec 10 2012
EXAMPLE
2*5^2+3*7^2 = 197 and 2*7^2+3*5^2 = 173 are prime.
MATHEMATICA
Select[Range[20000], PrimeQ[2*#^2 + 3*(# + 2)^2] && PrimeQ[3*#^2 + 2*(# + 2)^2] &] (* T. D. Noe, Dec 10 2012 *)
PROG
(PARI) for(a=1, 10000, c=a^2; b=(a+2)^2; if(isprime(2*c+3*b) && isprime(2*b+3*c), print1(a", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Dec 10 2012
STATUS
approved