OFFSET
1,1
EXAMPLE
If n=399 then 5*n^2 + 4 = 796009 (prime).
MATHEMATICA
Select[Range[1000], PrimeQ[5*#^2 + 4] &] (* Stefan Steinerberger, Feb 26 2006 *)
PROG
(PARI) is(n)=isprime(5*n^2+4) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Parthasarathy Nambi, Oct 18 2005
EXTENSIONS
More terms from Stefan Steinerberger, Feb 26 2006
STATUS
approved