Number of 6-ary Lyndon words with trace 1 mod 6.

Terms

a(0) =1a(1) =3a(2) =12a(3) =54a(4) =259a(5) =1296a(6) =6665a(7) =34992a(8) =186624a(9) =1007769a(10) =5496925a(11) =30233088a(12) =167444795a(13) =932906715a(14) =5224277604a(15) =29386561536a(16) =165947641615a(17) =940369969152