A177030 Numbers k such that 11^k + 3^k - 1 is prime.
1, 7, 9, 33, 127, 153, 2327, 3607, 14803, 16431
Offset: 1
Examples
7 is in the sequence, because 11^7 + 3^7 - 1 = 19489357 is prime.
Programs
-
Magma
[n: n in [0..1500]|IsPrime(11^n+3^n-1^n)]
-
PARI
is(n)=ispseudoprime(11^n+3^n-1) \\ Charles R Greathouse IV, Jun 13 2017
Formula
A177027(n) = 11^a(n)+3^a(n)-1.
Extensions
a(7)-a(8) from Daniel Starodubtsev, Apr 06 2020
a(9)-a(10) from Michael S. Branicky, Jul 15 2023
Comments