OFFSET
1,2
COMMENTS
These primes are represented in the numeral system described in A235860 with the digit "2" followed to the right with k-1 "12" strings.
EXAMPLE
For n = 2, (2^5 - 2)/3 + 1 = 11, which is prime, so 2 is in the sequence.
PROG
(PARI) isok(n) = isprime((2^(2*n+1) -2)/3 + n-1); \\ Michel Marcus, Jan 28 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Robin Garcia, Jan 28 2014
EXTENSIONS
a(1) inserted and a(15)-a(17) from Michael S. Branicky, Jul 29 2024
STATUS
approved