Octodecinary is a number system where the base is 18 and 7^3, 7^4 and 7^6 are palindromes. Full Repetend Prime Numbers: 5, 11, 29, 37, 43, 53, 61, 67, 83, 101, 107, 109, 139, 149, 157, 163, 173, 179, 181, 197, 227, 251, 269, 277, 283, 293, 317, 347, 349, 379, 389, 397, 419, 421, 461
