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

A056279

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

Terms

    a(0) =0a(1) =0a(2) =1a(3) =6a(4) =25a(5) =89a(6) =301a(7) =960a(8) =3024a(9) =9305a(10) =28501a(11) =86430a(12) =261625a(13) =788669a(14) =2375075a(15) =7140720a(16) =21457825a(17) =64435896a(18) =193448101a(19) =580597110a(20) =1742343323a(21) =5228050949a(22) =15686335501a(23) =47063113320a(24) =141197991000a(25) =423610488665

External references