OFFSET
1,1
COMMENTS
Primes of the form 4n^2 - 8n - 9.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..3000
EXAMPLE
For n=3, a(3)=3; n=7, a(7)=131; n=241, a(241)=230387
MATHEMATICA
Select[Range[4, 1000]^2-13, PrimeQ]
PROG
(Magma) [a: n in [4..600] | IsPrime(a) where a is n^2-13];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 18 2009
EXTENSIONS
Edited by N. J. A. Sloane, Jun 23 2010
STATUS
approved