Number of n-bead ternary necklaces (no turning over allowed) that avoid the subsequence 110.

Terms

a(0) =1a(1) =3a(2) =6a(3) =10a(4) =21a(5) =42a(6) =103a(7) =237a(8) =603a(9) =1519a(10) =3942a(11) =10257a(12) =27131a(13) =71940a(14) =192462a(15) =516933a(16) =1395636a(17) =3781356a(18) =10283911a(19) =28050600a(20) =76732047a(21) =210414811a(22) =578330649a(23) =1592821005a(24) =4395261552a(25) =12149386569a(26) =33637309323a(27) =93267459520a(28) =258961863288a(29) =719938597227