A135157 Number of primitive (no repeated characters) and irreducible (not the concatenation of generatable strings) strings obtained from abc by iterated repetition of substrings in place.
1, 0, 2, 0, 3, 1, 4, 0, 5, 2, 6, 0, 7, 3, 8, 0, 9, 6, 10, 0, 11, 12, 12, 4, 13, 24, 14, 23, 15, 54, 16, 91, 17, 149, 18, 326, 19, 484, 20, 1144, 21, 1741, 22, 4015, 23, 6589, 24, 14296, 25, 25299, 26, 52077, 27, 97264, 28, 193781, 29, 373996, 30, 733076
Offset: 0