A094963 Numbers k such that 2^k - 3*k is prime.

5, 7, 19, 23, 87, 107, 255, 1539, 2387, 4457, 5623, 15761, 22735, 27241, 86447

Offset: 1

Author

Robert G. Wilson v, May 26 2004

Keywords

• nonn
• more

Comments

a(16) > 140000. - Michael S. Branicky, Jul 27 2024

Crossrefs

Cf. A093988 (2^k + 3*k is prime).

Programs

Mathematica

Do[ If[ PrimeQ[2^n - 3n], Print[n]], {n, 1, 15000, 2}]

PARI

is(k) = ispseudoprime(2^k-3*k); \\ Jinyuan Wang, Feb 03 2020

Extensions

a(12)-a(14) from Jinyuan Wang, Feb 03 2020

a(15) from Michael S. Branicky, May 21 2023