Number of 4-ary Lyndon words of length n over Z_4 with trace 1 and subtrace 1.

Terms

a(0) =0a(1) =0a(2) =0a(3) =4a(4) =16a(5) =53a(6) =169a(7) =512a(8) =1706a(9) =6144a(10) =23040a(11) =87380a(12) =327680a(13) =1217097a(14) =4509419a(15) =16777216a(16) =62914560a(17) =237677216a(18) =902430720a(19) =3435973836a(20) =13102206738a(21) =50026607709a(22) =191312873561a(23) =733007751680