A211950 Number of distinct finite languages over binary alphabet, whose minimum regular expression has ordinary length n.

4, 4, 11, 28, 63, 156, 358, 888, 2194, 5665

Offset

1,1

Links

Table of n, a(n) for n=1..10.

Hermann Gruber, Jonathan Lee, and Jeffrey Shallit, Enumerating regular expressions and their languages, arXiv:1204.4982v1 [cs.FL]

Crossrefs

Sequence in context: A048223 A358825 A214112 * A014012 A371550 A273391

Adjacent sequences: A211947 A211948 A211949 * A211951 A211952 A211953

Keyword

nonn,hard

Author

Hermann Gruber, Apr 26 2012

Status

approved