Number of n-bead necklaces labeled with numbers 1..3 not allowing reversal, with no adjacent beads differing by more than 1.

A208772

Number of n-bead necklaces labeled with numbers 1..3 not allowing reversal, with no adjacent beads differing by more than 1.

Terms

    a(0) =3a(1) =5a(2) =7a(3) =12a(4) =19a(5) =39a(6) =71a(7) =152a(8) =315a(9) =685a(10) =1479a(11) =3294a(12) =7283a(13) =16359a(14) =36791a(15) =83312a(16) =189123a(17) =431393a(18) =986247a(19) =2262308a(20) =5200851a(21) =11985863a(22) =27676615a(23) =64034954a(24) =148406243a(25) =344507805a(26) =800902879a(27) =1864502926a(28) =4346071603a(29) =10142619039

External references