OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
23, (23-7)/8=2, and 8*23+7=191 are all prime.
MATHEMATICA
Select[Prime[Range[5000]], AllTrue[{(#-7)/8, 8#+7}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 24 2015 *)
PROG
(PARI) isok(p) = isprime(p) && isprime(8*p+7) && ((p % 8)==7) && isprime((p-7)/8); \\ Michel Marcus, Oct 16 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Mar 14 2009
STATUS
approved