A033016 Numbers n such that every run of digits of n in base 3 has length >=2.

4, 8, 13, 26, 36, 40, 44, 72, 76, 80, 108, 117, 121, 125, 134, 216, 229, 234, 238, 242, 324, 328, 332, 351, 360, 364, 368, 377, 396, 400, 404, 648, 652, 656, 684, 688, 692, 702, 715, 720, 724, 728, 972, 976, 980, 985, 998, 1053