1,2

Searched up to 76856*2^100000 - 1 (9607*2^100003 - 1 is the format in the Yves Gallot's Proth Program)

Table of n, a(n) for n=1..24.

Y. Gallot, Proth.exe: Windows Program for Finding Large Primes

a(n) = least integer greater than a(n-1) such that a(n-1)*2^a(n) - 1 is prime

Sequence in context: A067938 A306073 A018457 * A112777 A188972 A047612

Adjacent sequences: A046806 A046807 A046808 * A046810 A046811 A046812

hard,nonn

Chad Davis (cad16(AT)po.cwru.edu)

approved