Originally Posted by enzocreti
344 and 559 are multiple of 43 and congruent to 1 mod a Mersenne prime
344 is infact congruent to 1 mod 7 (the greatest factor is 7) (3441)=7*7*7 (the greatest factor is 7)
559 is congruent to 1 mod 31 (the greatest factor is 31) (558=...*31)
344 and 559 are sum of two positive cubes
are there other number k that are multiple of 43, sum of two positive cubes and such that the greatest factor of (k1) is a Mersenne prime?
