Is anyone able to find the demonstration of the following Mersenne conjecture?

for j=3, d=2*p*j+1=6*p+1 divide M(p)=2^p-1 if and only if

d is prime

and mod(d,8)=7

and p prime

and there exists integer n and i such that: d=4*n^2 + 3*(3+6*i)^2

This conjecture has been numericaly tested for p up to 10^11 and is a particular case of one of three new Mersenne and Cunningham conjectures that I have introduced in the Math Mersenne numbers forum four weeks ago (http://mersenneforum.org/showthread.php?t=9945)

But unfortunately up to now, no one of the three conjectures has been demonstrated. On this forum you will also find one numerical example (pdf file) for each of the three conjectures (see thread #20, #25 and #38)

Best Regards,

Olivier Latinne