A022339 Index of 3^n within sequence of numbers of form 3^i*5^j.

1, 2, 4, 7, 10, 14, 19, 24, 30, 37, 44, 52, 61, 70, 80, 91, 102, 114, 127, 140, 154, 169, 185, 201, 218, 236, 254, 273, 293, 313, 334, 356, 378, 401, 425, 449, 474, 500, 526, 553, 581, 609, 638, 668, 699, 730, 762, 795, 828, 862, 897, 932, 968, 1005, 1042, 1080, 1119