A031323 Least k such that base 10 representation of n begins at s(k), where s=A031312.
1, 16, 2, 36, 3, 56, 4, 76, 5, 96, 6, 17, 1, 37, 10, 57, 12, 77, 14, 246, 16, 276, 18, 306, 20, 336, 22, 366, 24, 396, 9, 19, 28, 39, 2, 59, 32, 79, 34, 546, 36, 576, 38, 606, 40, 636, 42, 666, 44, 696, 11, 21, 31, 41, 50, 61, 3, 81, 54, 846
Offset: 1