Number classes

Basic
Natural numbers (or nonnegative integers): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, X, B, J, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1X, 1B, 1J, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 2X, 2B, 2J, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 3X, 3B, 3J, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 4X, 4B, 4J, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 5X, 5B, 5J, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 6X, 6B, 6J, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 7X, 7B, 7J, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 8X, 8B, 8J, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 9X, 9B, 9J, X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, XX, XB, XJ, B0, B1, B2, B3, B4, B5, B6, B7, B8, B9, BX, BB, BJ, J0, J1, J2, J3, J4, J5, J6, J7, J8, J9, JX, JB, JJ, 100, ...

Positive integers: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, X, B, J, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1X, 1B, 1J, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 2X, 2B, 2J, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 3X, 3B, 3J, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 4X, 4B, 4J, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 5X, 5B, 5J, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 6X, 6B, 6J, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 7X, 7B, 7J, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 8X, 8B, 8J, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 9X, 9B, 9J, X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, XX, XB, XJ, B0, B1, B2, B3, B4, B5, B6, B7, B8, B9, BX, BB, BJ, J0, J1, J2, J3, J4, J5, J6, J7, J8, J9, JX, JB, JJ, 100, ...

Even numbers (or multiples of 2): 0, 2, 4, 6, 8, X, J, 11, 13, 15, 17, 19, 1B, 20, 22, 24, 26, 28, 2X, 2J, 31, 33, 35, 37, 39, 3B, 40, 42, 44, 46, 48, 4X, 4J, 51, 53, 55, 57, 59, 5B, 60, 62, 64, 66, 68, 6X, 6J, 71, 73, 75, 77, 79, 7B, 80, 82, 84, 86, 88, 8X, 8J, 91, 93, 95, 97, 99, 9B, X0, X2, X4, X6, X8, XX, XJ, B1, B3, B5, B7, B9, BB, J0, J2, J4, J6, J8, JX, JJ, ...

Odd numbers: 1, 3, 5, 7, 9, B, 10, 12, 14, 16, 18, 1X, 1J, 21, 23, 25, 27, 29, 2B, 30, 32, 34, 36, 38, 3X, 3J 41, 43, 45, 47, 49, 4B, 50, 52, 54, 56, 58, 5X, 5J, 61, 63, 65, 67, 69, 6B, 70, 72, 74, 76, 78, 7X, 7J, 81, 83, 85, 87, 89, 8B, 90, 92, 94, 96, 98, 9X, 9J, X1, X3, X5, X7, X9, XB, B0, B2, B4, B6, B8, BX, BJ, J1, J3, J5, J7, J9, JB, 100...

Multiples of a number
Multiples of 3: 0, 3, 6, 9, J, 12, 15, 18, 1B, 21, 24, 27, 2X, 30, 33, 36, 39, 3J, 42, 45, 48, 4B, 51, 54, 57, 5X, 60, ...

Multiples of 4: 0, 4, 8, J, 13, 17, 1B, 22, 26, 2X, 31, 35, 39, 40, 44, 48, 4J, 53, 57, 5B, 62, 66, 6X, 71, 75, 79, 80, ...

Multiples of 5: 0, 5, X, 12, 17, 1J, 24, 29, 31, 36, 3B, 43, 48, 50, 55, 5X, 62, 67, 6J, 74, 79, 81, 86, 8B, 93, 98, X0, ...

Multiples of 6: 0, 6, J, 15, 1B, 24, 2X, 33, 39, 42, 48, 51, 57, 60, 66, 6J, 75, 7B, 84, 8X, 93, 99, X2, X8, B1, B7, J0, ...

Multiples of 7: 0, 7, 11, 18, 22, 29, 33, 3X, 44, 4B, 55, 5J, 66, 70, 77, 81, 88, 92, 99, X3, XX, B4, BB, J5, JJ, 106, 110, ...

Multiples of 8: 8, 13, 1B, 26, 31, 39, 44, 4J, 57, 62, 6X, 75, 80, 88, 93, 9B, X6, B1, B9, J4, JJ, 107, 112, 11X, 125, 130, ...

Multiples of 9: 9, 15, 21, 2X, 36, 42, 4B, 57, 63, 6J, 78, 84, 90, 99, X5, B1, BX, J6, 102, 10B, 117, 123, 12J, 138, 144, 150, ...

Multiples of X: X, 17, 24, 31, 3B, 48, 55, 62, 6J, 79, 86, 93, X0, XX, B7, J4, 101, 10B, 118, 125, 132, 13J, 149, 156, 163, 170, ...

Multiples of B: B, 19, 27, 35, 43, 51, 5J, 6X, 78, 86, 94, 94, X2, B0, BB, J9, 107, 115, 123, 131, 13J, 14X, 158, 166, 174, 182, 190, ...

Multiples of J: J, 1B, 2X, 39, 48, 57, 66, 75, 84, 93, X2, B1, J0, JJ, 10B, 11X, 129, 138, 147, 156, 165, 174, 183, 192, 1X1, 1B0, ...

Multiples of 10: 10, 20, 30, 40, 50, 60, 70, 80, 90, X0, B0, J0, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 1X0, 1B0, 1J0, 200, ...