A131210 Numbers k such that 24k - 1 is prime.

1, 2, 3, 7, 8, 10, 11, 13, 15, 16, 18, 20, 21, 25, 27, 30, 31, 35, 36, 37, 38, 41, 43, 46, 48, 51, 55, 57, 60, 62, 63, 65, 66, 67, 76, 77, 78, 85, 86, 87, 88, 92, 98, 100, 101, 102, 106, 108, 111, 112, 113, 120, 121, 122, 125, 126, 130, 132, 133, 140, 142, 147, 151, 153

Offset: 1

Author

Zak Seidov, Oct 29 2007

Keywords

• nonn
• easy

Comments

The complement is 4, 5, 6, 9, 12, 14, 17, 19, 22, 23, 24, ... and contains numbers of the form == 4 (mod 5), == 5 (mod 7), == 6 (mod 11), == 6 (mod 13), == 5 (mod 17) etc., so the complement is a superset of A182719. - R. J. Mathar, Jun 10 2020

Links

• Muniru A Asiru, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A182719.

Programs

GAP

Filtered([1..160],n->IsPrime(24*n-1)); # Muniru A Asiru, Feb 19 2018

Magma

[n: n in [0..500]|IsPrime(24*n-1)] // Vincenzo Librandi, Nov 23 2010

Maple

select(n->isprime(24*n-1),[$1..160]); # Muniru A Asiru, Feb 19 2018

Mathematica

Select[Range[150], PrimeQ[24*# - 1] &] (* Amiram Eldar, Mar 28 2024 *)

PARI

is(n)=isprime(24*n-1) \\ Charles R Greathouse IV, Jun 06 2017