OFFSET
1,1
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..10000
EXAMPLE
17 is in the sequence because, given x = (17 - 1)/2 = 8, we have 8^2 + 8 + 41 = 113 which is prime.
MATHEMATICA
Select[Prime[Range[100]], PrimeQ[((# - 1)/2)^2 + ((# - 1)/2) + 41] &] (* Alonso del Arte, Aug 21 2012 *)
PROG
(PARI) for(x=1, 1e3, if(ispseudoprime(2*x+1), if(ispseudoprime(x^2+x+41), print1(2*x+1, ", ")))) \\ Felix Fröhlich, Aug 16 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Aug 21 2012
STATUS
approved