OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
FORMULA
3*a(n)*(a(n)-1)+1 = A165683(n).
MATHEMATICA
Select[Prime[Range[800]], PrimeQ[3 # (# - 1) + 1]&] (* Vincenzo Librandi, Apr 15 2013 *)
PROG
(Magma) [p: p in PrimesUpTo(1600) | IsPrime(3*p*(p-1)+1)]; // Vincenzo Librandi, Apr 15 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Sep 24 2009
EXTENSIONS
2 and 3 inserted by R. J. Mathar, Sep 26 2009
STATUS
approved