Do you think that the formula p = 6n + 1 where n is a whole number, will produce a prime number more than 50% of the time?
6(1) + 1 = 7
6(2) + 1 = 13
6(3) + 1 = 19
6(4) + 1 = 25
6(5) + 1 = 31
6(6) + 1 = 37
6(7) + 1 = 43
6(8) + 1 = 49
Clearly no.