A211486 Primes of the form 5+3*2^k.

11, 17, 29, 53, 101, 197, 389, 773, 49157, 196613, 1572869, 12582917, 50331653, 402653189, 1610612741, 12884901893, 824633720837, 54043195528445957, 432345564227567621, 3458764513820540933, 226673591177742970257413, 59421121885698253195157962757

Offset: 1

Author

Vincenzo Librandi, Apr 13 2012

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..40

Crossrefs

Cf. A057913 (n such that 3*2^n + 5 is prime).

Cf. A057197, A144487.

Programs

Magma

[ a: n in [0..250] | IsPrime(a) where a is 5+3*2^n ];

Mathematica

Select[5+2^Range[0,2000]*3,PrimeQ]

PARI

{for(n=0, 80, if(isprime(k=5+3*2^n), print1(k, ", ")))}