Finding Primes the Euler Way
Trying to find a prime number seems difficult. You have to test it against divisibility by all of the primes that are smaller. But what if there were a formula?
Take a counting number, multiply it by itself, subtract it from the result and then add 41
1*1 = 1; 1-1 = 0; 0+41 = 41. That's prime.
2*2 = 4; 4-2 = 2; 2+41 = 43. That's prime.
3*3 = 9; 9-3 = 6; 6+41 = 47. That's prime, too.
4*4 = 16; 16-4=12; 12+41= 53. That's also prime.
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