Number of primitive (aperiodic) words of length n which contain exactly three different symbols.

A056268

Number of primitive (aperiodic) words of length n which contain exactly three different symbols.

Terms

    a(0) =0a(1) =0a(2) =6a(3) =36a(4) =150a(5) =534a(6) =1806a(7) =5760a(8) =18144a(9) =55830a(10) =171006a(11) =518580a(12) =1569750a(13) =4732014a(14) =14250450a(15) =42844320a(16) =128746950a(17) =386615376a(18) =1160688606a(19) =3483582660a(20) =10454059938a(21) =31368305694a(22) =94118013006a(23) =282378679920a(24) =847187946000

External references