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