Numbers of the form 6^j +7^k and pg primes
 

Pg(215) pg(69660) pg(92020) pg(541456) are probable primes with 215, 69660, 92020 and 541456 of the form 43s


I realized that 215, 69660, 92020 and 541456 are congruent to + or - (7^3+1) mod (6^3+7^3)

344=7^3+1=(43*8)
6^3+7^3=13*43

8, 13, 43are numbers of the form 6^j+7^k with j, k>=0

So it should be correct to say that

215, 69660, 92020, 541456 are congruent to + or - (6^j+7^k)*(6^x+7^y) mod( (6^z+7^w)*(6^b+7^c))
With nonnegative j k x y z w b c