OFFSET
1,1
COMMENTS
Or, 2 along with primes p such that Sum_{x=1..p} (1 - (-1)^x*x) is prime. - Juri-Stepan Gerasimov, Jul 14 2009
Apart from the first term, primes of the form 4*k-1 such that 6*k-1 is also prime. - Charles R Greathouse IV, Nov 09 2011
If both p and q are in A158709 and p + q == 2 (mod 4), then A006370(A006370(p + q)) = A006370((p + q)/2) = 3*(p + q)/2 + 1 is the sum of the two primes p+ceiling(p/2) and q+ceiling(q/2). - Roderick MacPhee, Feb 23 2018
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
MATHEMATICA
lst={}; Do[p=Prime[n]; If[PrimeQ[Ceiling[p/2]+p], AppendTo[lst, p]], {n, 6!}]; lst
Select[Prime@ Range@ 250, PrimeQ@ Ceiling[3#/2] &] (* Vincenzo Librandi, Apr 15 2013 and slightly modified by Robert G. Wilson v, Feb 26 2018 *)
PROG
(PARI) forprime(p=2, 1e4, if(isprime(p+ceil(p/2)), print1(p", "))) \\ Charles R Greathouse IV, Nov 09 2011
(PARI) print1(2); forprime(p=3, 1e4, if(p%4==3&&isprime(p\4*6+5), print1(", "p))) \\ Charles R Greathouse IV, Nov 09 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vladimir Joseph Stephan Orlovsky, Mar 24 2009
EXTENSIONS
Corrected by Charles R Greathouse IV, Mar 18 2010
STATUS
approved