OFFSET
1,1
COMMENTS
Conjecture: 2^a(n)-1 is not prime; in other words, these primes are included in A054723.
2*a(n) + 7 is a square. - Vincenzo Librandi, Apr 09 2015
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Table[2 n^2 + 6 n + 1, {n, 2000}], PrimeQ] (* Vincenzo Librandi, Jul 26 2012 *)
PROG
(Magma) [a: n in [0..300] | IsPrime(a) where a is 2*n^2+6*n+1]; // Vincenzo Librandi, Jul 26 2012
CROSSREFS
Primes in A059993.
Subsequence of A093838.
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 20 2010
EXTENSIONS
Removed an obviously incorrect part of the definition - R. J. Mathar, Apr 21 2010
STATUS
approved