Number of n-bead necklaces labeled with numbers 1..4 not allowing reversal, with no adjacent beads differing by more than 1.

A208773

Number of n-bead necklaces labeled with numbers 1..4 not allowing reversal, with no adjacent beads differing by more than 1.

Terms

    a(0) =4a(1) =7a(2) =10a(3) =18a(4) =30a(5) =65a(6) =128a(7) =293a(8) =658a(9) =1544a(10) =3622a(11) =8711a(12) =20924a(13) =50889a(14) =124150a(15) =304718a(16) =750334a(17) =1855429a(18) =4600696a(19) =11442853a(20) =28528618a(21) =71294416a(22) =178529670a(23) =447923761a(24) =1125756860a(25) =2833917147a(26) =7144466842a(27) =18036449390a(28) =45591671454a(29) =115381885423

External references