A211945 Number of distinct regular languages over 4-ary alphabet, whose minimum regular expression has reverse Polish length n.

6, 4, 26, 62, 244, 920, 3133, 13529, 48388, 208634

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

Cf. A211946.

Sequence in context: A137174 A129886 A133837 * A121682 A237425 A191567

Adjacent sequences: A211942 A211943 A211944 * A211946 A211947 A211948

Keyword

nonn,more

Author

Hermann Gruber, Apr 26 2012

Status

approved