OFFSET
1,1
COMMENTS
Apart from the first term, primes of the form 4n+1 such that 6n+1 is also prime. [Charles R Greathouse IV, Nov 09 2011]
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
lst={}; Do[p=Prime[n]; If[PrimeQ[Floor[p/2]+p], AppendTo[lst, p]], {n, 6!}]; lst
Select[Prime[Range[300]], PrimeQ[Floor[# / 2] + #]&] (* Vincenzo Librandi, Apr 15 2013 *)
PROG
(PARI) forprime(p=2, 1e4, if(isprime(p+p\2), print1(p", "))) \\ Charles R Greathouse IV, Nov 09 2011
(PARI) print1(2); forprime(p=3, 1e4, if(p%4==1&&isprime(p\4*6+1), print1(", "p))) \\ Charles R Greathouse IV, Nov 09 2011
(Magma) [p: p in PrimesUpTo(1800) | IsPrime(p+ (p div 2))]; // Vincenzo Librandi, Apr 15 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vladimir Joseph Stephan Orlovsky, Mar 24 2009
STATUS
approved