A143384 Duplicate of A139426.

1, 5, 1, 5, 11, 11, 17, 19, 23, 97, 127, 145, 167, 269, 767, 479, 3307, 1453, 18007, 2357, 599, 17669, 5527, 3191, 3251, 70249, 147773, 39637

Offset: 1

Author

Pierre CAMI, Aug 11 2008

Keywords

• dead

Comments

All primes certified using PFGW from Primeform group.

Examples

			(2^2-1)*(2^2-1+1)-1=11 prime 2^2-1=M(1) so a(1)=1
(2^3-1)*(2^3-1+1)-1=55 composite
(2^3-1)*(2^3-1+3)-1=69 composite
(2^3-1)*(2^3-1+5)-1=83 prime 2^3-1=M(2) so a(2)=5
		

Crossrefs

Cf. A000043 (Mersenne prime exponents), A143385.

Extensions

Missing terms 2357 and 599 inserted by Jens Kruse Andersen, Jul 30 2014