A073140 Sum of the largest and smallest number having in binary representation the same number of 0's and 1's as n.

0, 2, 4, 6, 8, 11, 11, 14, 16, 21, 21, 25, 21, 25, 25, 30, 32, 41, 41, 47, 41, 47, 47, 53, 41, 47, 47, 53, 47, 53, 53, 62, 64, 81, 81, 91, 81, 91, 91, 99, 81, 91, 91, 99, 91, 99, 99, 109, 81, 91, 91, 99, 91, 99, 99, 109, 91, 99, 99, 109, 99, 109, 109, 126, 128, 161, 161, 179