A037971 n-th number whose maximal base 2 run length is 4.

15, 16, 30, 33, 47, 48, 60, 61, 66, 67, 79, 80, 94, 97, 111, 112, 120, 121, 122, 123, 132, 133, 134, 135, 143, 144, 158, 161, 175, 176, 188, 189, 194, 195, 207, 208, 222, 225, 239, 240, 241, 242, 243, 244, 245, 246, 247, 264, 265