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

A208771

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

Terms

    a(0) =1a(1) =3a(2) =7a(3) =18a(4) =41a(5) =117a(6) =299a(7) =861a(8) =2413a(9) =6955a(10) =19943a(11) =57974a(12) =168013a(13) =489789a(14) =1428611a(15) =4177232a(16) =12226997a(17) =35847123a(18) =105200351a(19) =309086838a(20) =908931221a(21) =2675276801a(22) =7880255915a(23) =23228969891a(24) =68518137777a(25) =202231890207a(26) =597228362551

External references