A modification of the Eberhart's conjecture proposed by Wagstaff (1983) which proposes that if is the th prime such that is a Mersenne prime, then

where is the Euler-Mascheroni constant.

A modification of the Eberhart's conjecture proposed by Wagstaff (1983) which proposes that if is the th prime such that is a Mersenne prime, then

where is the Euler-Mascheroni constant.

Weisstein, Eric W. "Wagstaff's Conjecture."
From *MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/WagstaffsConjecture.html