A155886 Least k such that 2^(2^k) = n (mod k).

1, 3, 14, 11, 6, 1941491, 10, 83, 31, 13, 123, 35, 71, 27, 34913, 241, 18, 8059, 34, 349, 44, 25, 39, 100867561, 76, 231, 253, 66203, 57, 227, 139, 45, 184, 37, 111, 97, 55, 41, 103, 1099, 81, 66791, 53