I discovered an interesting numerical sequence:

     1,  2,  3,  4,  5,  6,  7,  8,  9,
 2,  3,  5,  7,  9, 11, 13, 15, 17, 19,
 6,  7,  8, 11, 14, 17, 20, 23, 26, 29,
12, 13, 14, 15, 19, 23, 27, 31, 35, 39,
20, 21, 22, 23, 24, 29, 34, 39, 44, 49,
30, 31, 32, 33, 34, 35, 41, 47, 53, 59,
42, 43, 44, 45, 46, 47, 48, 55, 62, 69,
56, 57, 58, 59, 60, 61, 62, 63, 71, 79,
72, 73, 74, 75, 76, 77, 78, 79, 80, 89,
90, 91, 92, 93, 94, 95, 96, 97, 98, 99

I’m not sure if its properties will be useful, but it is easy to calculate.

Every number from 1 to 99, expressed in decimal form, converted to the lowest possible base: so 10 becomes 2 in binary, 11 becomes 3 in binary, 12 becomes 5 in base 3, 13 becomes 7 in base 4, etc.