A126058 Exponents p of the Mersenne primes 2^p - 1 (see A000043) read mod 18.

2, 3, 5, 7, 13, 17, 1, 13, 7, 17, 17, 1, 17, 13, 1, 7, 13, 13, 5, 13, 5, 5, 17, 11, 11, 7, 1, 5, 1, 1, 1, 11, 5, 1, 11, 11, 5, 5, 1, 1, 13, 5, 7, 11