A236524 - OEIS

A236524

Numbers n such that n^3 - n +/- 1 are twin primes.

2, 4, 11, 14, 15, 21, 31, 35, 41, 45, 111, 130, 136, 140, 155, 176, 189, 221, 230, 239, 274, 316, 406, 414, 441, 465, 466, 504, 521, 561, 570, 580, 584, 591, 686, 689, 696, 759, 834, 836, 860, 869, 904, 960, 1026, 1159, 1379, 1539, 1614, 1625, 1660

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..2600

EXAMPLE

561^3 - 561 + 1 (176557921) and 561^3 - 561 - 1 (176557919) are twin primes. Thus, 561 is a member of this sequence.

MATHEMATICA

Select[Range[2000], PrimeQ[#^3 - # - 1] && PrimeQ[#^3 - # + 1] &] (* Vincenzo Librandi, Jan 30 2018 *)

PROG

(Python)

import sympy

from sympy import isprime

{print(n) for n in range(10**4) if isprime(n**3-n-1) and isprime(n**3-n+1)}

(Magma) [n: n in [1..2000] | IsPrime(n^3-n-1) and IsPrime(n^3-n+1)]; // Vincenzo Librandi, Jan 30 2018

CROSSREFS

Intersection of A126421 and A236477.

Sequence in context: A018525 A102935 A287210 * A295968 A038193 A227456

Adjacent sequences: A236521 A236522 A236523 * A236525 A236526 A236527

KEYWORD

nonn

AUTHOR

Derek Orr, Jan 27 2014

STATUS

approved