Number of 4-ary Lyndon words of length n over Z_4 with trace 2 and subtrace 1.

Terms

a(0) =0a(1) =0a(2) =2a(3) =4a(4) =16a(5) =36a(6) =128a(7) =440a(8) =1706a(9) =6560a(10) =24576a(11) =90046a(12) =327680a(13) =1197824a(14) =4438966a(15) =16645120a(16) =62914560a(17) =238609052a(18) =905969664a(19) =3442670796a(20) =13102206738a(21) =49977704448a(22) =191126044672a(23) =732649663000