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

A274019

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

Terms

    a(0) =1a(1) =4a(2) =10a(3) =23a(4) =66a(5) =192a(6) =636a(7) =2092a(8) =7228a(9) =25175a(10) =89212a(11) =318808a(12) =1150444a(13) =4177908a(14) =15268494a(15) =56078527a(16) =206903020a(17) =766342160a(18) =2848351388a(19) =10619472284a(20) =39702648534a(21) =148806583111a(22) =558999381656

External references