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

1,1

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: A379437 A083885 A350649 * A230942 A188570 A009352

Adjacent sequences: A211951 A211952 A211953 * A211955 A211956 A211957

Keyword

nonn,hard

Author

Hermann Gruber, Apr 26 2012

Status

approved