A236547 n such that (2^(2n + 1) - 2)/3 + n - 1 is prime.

2, 4, 10, 14, 28, 54, 62, 124, 592, 1088, 3154, 3920, 5564

Offset

1,1

Comments

These primes are represented in the numeral system described in A235860 with the digit "2" followed to the right with n-1 "12" strings.

Links

Table of n, a(n) for n=1..13.

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

Cf. A235860.

Sequence in context: A081115 A053417 A082230 * A078775 A351160 A056392

Adjacent sequences: A236544 A236545 A236546 * A236548 A236549 A236550

Keyword

nonn

Author

Robin Garcia, Jan 28 2014

Status

approved