A025744 Index of 10^n within sequence of numbers of form 6^i*10^j.

1, 3, 6, 10, 16, 23, 31, 40, 51, 63, 76, 91, 107, 124, 142, 162, 183, 205, 229, 254, 280, 307, 336, 366, 397, 430, 464, 499, 535, 573, 612, 652, 694, 737, 781, 826, 873, 921, 970, 1021, 1073, 1126, 1180, 1236, 1293, 1351, 1411, 1472, 1534, 1597, 1662, 1728, 1795