A025696 Index of 3^n within sequence of numbers of form 3^i*4^j.

1, 2, 4, 7, 11, 15, 20, 26, 33, 41, 49, 58, 68, 79, 91, 103, 116, 130, 145, 161, 177, 194, 212, 231, 251, 271, 292, 314, 337, 360, 384, 409, 435, 462, 489, 517, 546, 576, 607, 638, 670, 703, 737, 772, 807, 843, 880, 918, 957, 996, 1036, 1077, 1119, 1162, 1205, 1249