A211954 Number of distinct finite languages over 4-ary alphabet, whose minimum regular expression has ordinary length n.
6, 16, 74, 336, 1474, 6560, 28861, 128720, 578033, 2624460
Offset: 1
Links
- Hermann Gruber, Jonathan Lee, and Jeffrey Shallit, Enumerating regular expressions and their languages, arXiv:1204.4982v1 [cs.FL]