A055126 Base 16 complement of n (write n in base 16, then replace each digit by its base 16 negative).

0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 240, 255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 224, 239, 238, 237, 236, 235, 234, 233, 232, 231, 230, 229, 228, 227, 226, 225, 208, 223, 222, 221, 220, 219, 218, 217, 216, 215