OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
2^9+9 = 521 is prime and 2^9-9 = 503 is prime. Thus, 2 is a member of this sequence.
MATHEMATICA
Select[Range[50000], AllTrue[#^9+{9, -9}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 12 2015 *)
PROG
(Python)
import sympy
from sympy import isprime
def TwoBoth(x):
..for k in range(10**6):
....if isprime(k**x+x) and isprime(k**x-x):
......print(k)
TwoBoth(9)
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, Mar 20 2014
STATUS
approved