A043734 Numbers n such that number of runs in the base 2 representation of n is congruent to 1 mod 6.

1, 3, 7, 15, 31, 63, 85, 127, 149, 165, 169, 171, 173, 181, 213, 255, 277, 293, 297, 299, 301, 309, 325, 329, 331, 333, 337, 339, 343, 345, 347, 349, 357, 361, 363, 365, 373, 405, 421, 425, 427, 429, 437, 469, 511, 533, 549, 553