A211939 Number of distinct regular languages over unary alphabet, whose minimum regular expression has reverse Polish length n.

3, 1, 2, 2, 3, 4, 6, 7, 11, 15

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: A092155 A288725 A029336 * A010280 A318556 A292148

Adjacent sequences: A211936 A211937 A211938 * A211940 A211941 A211942

Keyword

nonn,more

Author

Hermann Gruber, Apr 26 2012

Status

approved