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

A211945

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

Terms

    a(0) =6a(1) =4a(2) =26a(3) =62a(4) =244a(5) =920a(6) =3133a(7) =13529a(8) =48388a(9) =208634

External references