OFFSET
1,1
COMMENTS
Or primes of the form Sum_{x=1..n-th prime} (1-(-1)^x*x). - Juri-Stepan Gerasimov, Jul 14 2009
Primes p such that (2*p-1)/3 is prime. - J. M. Bergot, Aug 19 2020
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
3+2=5, 7+4=11, 11+6=17, 19+10=29, 31+16=47, 47+24=71,.. r:3,7,11,19,31,47,59,67,71,127,131,151,167,179,211,239,307,311, ..A158709.
MAPLE
filter:= p -> isprime(p) and isprime((2*p-1)/3):
select(filter, [seq(i, i=5..10000, 6)]); # Robert Israel, Aug 19 2020
MATHEMATICA
lst={}; Do[r=Prime[n]; p=r+(r+1)/2; If[PrimeQ[p], AppendTo[lst, p]], {n, 6!}]; lst
Select[#+(#+1)/2&/@Prime[Range[300]], PrimeQ] (* Harvey P. Dale, Apr 30 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Jul 01 2009
EXTENSIONS
Edited by N. J. A. Sloane, Jul 18 2009
STATUS
approved