A103148 Numbers n such that 2^n+25229 is prime.

3, 5, 7, 9, 11, 19, 21, 29, 33, 41, 77, 81, 99, 101, 109, 119, 141, 145, 161, 163, 171, 183, 201, 209, 227, 241, 299, 303, 321, 367, 395, 413, 459, 501, 689, 777, 889, 989, 1317, 1839, 2027, 2197, 2571, 3041, 3143, 4541, 4701, 5265, 5463, 6449, 7061, 7289, 9291, 9663, 12287, 17441, 23033, 23297, 26543, 32939, 33543

Offset

1,1

Comments

This is the longest sequence that I have found of the class "2^n+/-(odd integer) is prime".

Links

Table of n, a(n) for n=1..61.

Example

2^3+25229 = 25237 is prime
2^11+25229 = 27277 is prime
2^2+25229 = 25233 = 3x13x647

Mathematica

Do[If[PrimeQ[2^n + 25229], Print[n]], {n, 33600}]

Prog

(PARI) is(n)=ispseudoprime(2^n+25229) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Cf. A094076, A000043.

Sequence in context: A071643 A039578 A033032 * A211138 A178995 A346604

Adjacent sequences: A103145 A103146 A103147 * A103149 A103150 A103151

Keyword

nonn

Author

Lei Zhou, Feb 03 2005

Status

approved