Number of 4-ary Lyndon words whose trace and subtrace are both 0 mod 4.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =11a(5) =44a(6) =169a(7) =588a(8) =1948a(9) =6560a(10) =23133a(11) =84565a(12) =317755a(13) =1198336a(14) =4509419a(15) =16909184a(16) =63409935a(17) =238609052a(18) =902444517a(19) =3429249843a(20) =13076666409a(21) =49977802752a(22) =191312873561a(23) =733365845820