0,2

If K is a member and K-1 is the neighboring prime then it must be a Merssenne's prime. Conjecture: sequence is infinite.

Table of n, a(n) for n=0..40.

Cf. A088256, A088257, A088258.

Sequence in context: A304250 A322793 A283052 * A123857 A217313 A101434

Adjacent sequences: A088256 A088257 A088258 * A088260 A088261 A088262

nonn

Amarnath Murthy, Sep 27 2003

Corrected and extended by Ray Chandler, Sep 28 2003

approved