A182375 Positive integers k such that k*2^k - 3 is prime.

2, 4, 5, 14, 16, 17, 34, 38, 133, 175, 218, 284, 1036, 1441, 1550, 2893, 2933, 3770

Offset: 1

Author

Patrick Devlin, Apr 26 2012

Keywords

• nonn

Comments

Similar to the Woodall primes, A050918.

The next term in this sequence is unknown; if it is infinite, the next term is greater than 8000.

Examples

			5 = 2*2^2 - 3;  61 = 4*2^4 - 3;  157 = 5*2^5 - 3
		

Crossrefs

Cf. A050918. Values for primes are A182352.

Programs

Maple

f:=n->n*2^n - 3:
S:={}:
for n from 0 to 300 do if(isprime(f(n))) then S:=S union {n}: fi: od