A239505 Numbers n such that n^9+9 and n^9-9 are prime.

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

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

Cf. A239346, A239417.

Sequence in context: A282999 A201242 A062585 * A002490 A179961 A160224

Adjacent sequences: A239502 A239503 A239504 * A239506 A239507 A239508

Keyword

nonn

Author

Derek Orr, Mar 20 2014

Status

approved