3 ms·
The not 49 and 91 rule combined with the rule that "a prime above 3 is always exactly 1 off being a multiple of 6" will get you flying through this test.
by AReallyGoodName 11y ago
The not 49 and 91 rule combined with the rule that "a prime above 3 is always exactly 1 off being a multiple of 6" will get you flying through this test.