A108062 Numbers k such that 2^(2k-1) + 2^k + 1 is prime.
1, 2, 3, 6, 10, 15, 79, 82, 142, 190, 499, 5071, 7350, 38646, 42619, 53347
Offset: 1
Links
- Jacques Basaldua, All Fermat and Mersenne numbers are squarefree.
Programs
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Mathematica
Do[ If[ PrimeQ[2^(2n - 1) + 2^n + 1], Print[n]], {n, 5500}] (* Robert G. Wilson v, Jun 03 2005 *) -
PARI
is(n)=ispseudoprime(2^(2*n-1)+2^n+1) \\ Charles R Greathouse IV, Jun 12 2017
Formula
a(n) = A006599(n) + 1.
Extensions
a(1) and a(12) from Robert G. Wilson v, Jun 03 2005
a(13) from Jeppe Stig Nielsen, Mar 28 2014
a(14)-a(16) from Michael S. Branicky, Jan 02 2025
Comments