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A239505
Numbers n such that n^9+9 and n^9-9 are prime.
1
2, 1642, 2870, 2948, 4238, 5480, 5920, 7502, 8210, 8248, 9328, 11572, 13538, 13610, 14818, 14908, 19298, 21022, 21890, 21988, 22340, 23000, 23252, 26282, 26380, 29168, 31660, 32602, 33338, 33650, 36220, 38248, 38422, 43490, 43910, 44948, 45188, 46048
OFFSET
1,1
COMMENTS
All numbers in this sequence are even.
Intersection of A239346 and A239417.
LINKS
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
Sequence in context: A375845 A201242 A062585 * A002490 A179961 A160224
KEYWORD
nonn
AUTHOR
Derek Orr, Mar 20 2014
STATUS
approved