Number of distinct finite languages over 4-ary alphabet, whose minimum regular expression has reverse Polish length 2n-1.
A211946
Number of distinct finite languages over 4-ary alphabet, whose minimum regular expression has reverse Polish length 2n-1.
Terms
- a(0) =6a(1) =26a(2) =202a(3) =1917a(4) =20251a(5) =231152a(6) =2780936
External references
- oeis: A211946