A211952 Number of distinct finite languages over 3-ary alphabet, whose minimum regular expression has ordinary length n.

5, 9, 33, 117, 391, 1350, 4546, 15753, 55053, 196185

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: A323150 A116390 A028351 * A098640 A239546 A083832

Adjacent sequences: A211949 A211950 A211951 * A211953 A211954 A211955

Keyword

nonn,hard

Author

Hermann Gruber, Apr 26 2012

Status

approved