A211940 Number of distinct finite languages over unary alphabet, whose minimum regular expression has reverse Polish length 2n-1.

3, 2, 3, 5, 9, 14, 24, 41, 71, 118

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], 2012.

Crossrefs

Sequence in context: A241816 A243109 A206012 * A230664 A175717 A051701

Adjacent sequences: A211937 A211938 A211939 * A211941 A211942 A211943

Keyword

nonn,more

Author

Hermann Gruber, Apr 26 2012

Status

approved