A043686 a(n) = (1/2)*(n-th number whose base-2 representation has exactly 12 runs).
1365, 2389, 2645, 2709, 2725, 2729, 2730, 2731, 2733, 2741, 2773, 2901, 3413, 4437, 4693, 4757, 4773, 4777, 4778, 4779, 4781, 4789, 4821, 4949, 5205, 5269, 5285, 5289, 5290, 5291, 5293, 5301, 5333, 5397, 5413, 5417
Offset: 1