OFFSET
1,1
COMMENTS
All these primes are congruent to 1 mod 4 and to 5 mod 12.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = 2*A063909(n)-5. - Robert Israel, Feb 24 2016
MAPLE
select(t -> isprime(t) and isprime((t+5)/2), [seq(i, i=5..1000, 12)]); # Robert Israel, Feb 24 2016
MATHEMATICA
aa = {}; k = 5; Do[If[PrimeQ[(k + Prime[n])/2], AppendTo[aa, Prime[n]]], {n, 1, 500}]; aa
Select[Prime[Range[500]], PrimeQ[(5+#)/2]&] (* Harvey P. Dale, Apr 23 2011 *)
PROG
(PARI) forprime(p=2, 1e4, if(p%12!=5, next); if(isprime(p\2+3), print1(p", "))) \\ Charles R Greathouse IV, Jul 16 2011
(Magma) [p: p in PrimesInInterval(3, 2000) | IsPrime((5+p) div 2)]; // Vincenzo Librandi, Feb 25 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Oct 11 2008
STATUS
approved