Number of words of length 3n such that all letters of the binary alphabet occur at least once and are introduced in ascending order and which can be built by repeatedly inserting triples into the initially empty word.
A321032
Number of words of length 3n such that all letters of the binary alphabet occur at least once and are introduced in ascending order and which can be built by repeatedly inserting triples into the initially empty word.
Terms
- a(0) =3a(1) =18a(2) =97a(3) =530a(4) =2973a(5) =17059a(6) =99657a(7) =590562a(8) =3540463a(9) =21430266a(10) =130771375a(11) =803538099a(12) =4967127735a(13) =30866224823a(14) =192696614729
External references
- oeis: A321032