Another cool way to generate primes!
Step 1: Find the lowest common multiples incrementally.
lcm(1,2) = 2
lcm(1,2,3) = 6
lcm(1,2,3,4) = 12
lcm(1,2,3,4,5) = 60
lcm(1,2,3,4,5,6) = 60
lcm(1,2,3,4,5,6,7) = 420
lcm(1,2,3,4,5,6,7,8) = 840
lcm(1,2,3,4,5,6,7,8,9) = 2520
lcm(1,2,3,4,5,6,7,8,9,10) = 2520
lcm(1,2,3,4,5,6,7,8,9,10,11) = 27720
lcm(1,2,3,4,5,6,7,8,9,10,11,12) = 27720
lcm(1,2,3,4,5,6,7,8,9,10,11,12,13) = 360360
lcm(1,2,3,4,5,6,7,8,9,10,11,12,13,14) = 360360
lcm(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15) = 360360
lcm(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16) = 720720
lcm(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17) = 12252240
...and so on.
Step 2: Divide each result by the preceding result.
For example, lcm(1,2,3,4) / lcm(1,2,3) = 12/6 = 2.
You will obtain a list containing only prime numbers! Can you see why this is always the case?
[3, 2, 5, 1, 7, 2, 3, 1, 11, 1, 13, 1, 1, 2, 17, 1, 19, 1, 1, 1, 23, 1, 5, 1, 3, 1, 29, 1, 31, 2, 1, 1, 1, 1, 37, 1, 1, 1, 41, 1, 43, 1, 1, 1, 47, 1, 7, 1, 1, 1, 53, 1, 1, 1, 1, 1, 59, 1, 61, 1, 1, 2, 1, 1, 67, 1, 1, 1, 71, 1, 73, 1, 1, 1, 1, 1, 79, 1, 3, 1, 83, 1, 1, 1, 1, 1, 89, 1, 1, 1, 1, 1, 1, 1, 97, 1, 1, 1, 101, 1, 103, 1, 1, 1, 107, 1, 109, 1, 1, 1, 113, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 1, 5, 1, 127, 2, 1, 1, 131, 1, 1, 1, 1, 1, 137, 1, 139, 1, 1, 1, 1, 1, 1, 1, 1, 1, 149, 1, 151, 1, 1, 1, 1, 1, 157, 1, 1, 1, 1, 1, 163, 1, 1, 1, 167, 1, 13, 1, 1, 1, 173, 1, 1, 1, 1, 1, 179, 1, 181, 1, 1, 1, 1, 1, 1, 1, 1, 1, 191, 1, 193, 1, 1, 1, 197, 1, 199, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 211, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 223, 1, 1, 1, 227, 1, 229, 1, 1, 1, 233, 1, 1, 1, 1, 1, 239, 1, 241, 1, 3, 1, 1, 1, 1, 1, 1, 1, 251, 1, 1, 1, 1, 2, 257, 1, 1, 1, 1, 1, 263, 1, 1, 1, 1, 1, 269, 1, 271, 1, 1, 1, 1, 1, 277, 1, 1, 1, 281, 1, 283, 1, 1, 1, 1, 1, 17, 1, 1, 1, 293, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 307, 1, 1, 1, 311, 1, 313, 1, 1, 1, 317, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 331, 1, 1, 1, 1, 1, 337, 1, 1, 1, 1, 1, 7, 1, 1, 1, 347, 1, 349, 1, 1, 1, 353, 1, 1, 1, 1, 1, 359, 1, 19, 1, 1, 1, 1, 1, 367, 1, 1, 1, 1, 1, 373, 1, 1, 1, 1, 1, 379, 1, 1, 1, 383, 1, 1, 1, 1, 1, 389, 1, 1, 1, 1, 1, 1, 1, 397, 1, 1, 1, 401, 1, 1, 1, 1, 1, 1, 1, 409, 1, 1, 1, 1, 1, 1, 1, 1, 1, 419, 1, 421, 1, 1, 1, 1, 1, 1, 1, 1, 1, 431, 1, 433, 1, 1, 1, 1, 1, 439, 1, 1, 1, 443, 1, 1, 1, 1, 1, 449, 1, 1, 1, 1, 1, 1, 1, 457, 1, 1, 1, 461, 1, 463, 1, 1, 1, 467, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 479, 1, 1, 1, 1, 1, 1, 1, 487, 1, 1, 1, 491, 1, 1, 1, 1, 1, 1, 1, 499,...]