Number of 2n-bead necklaces labeled with numbers 1..6 not allowing reversal, with neighbors differing by exactly 1.

A208725

Number of 2n-bead necklaces labeled with numbers 1..6 not allowing reversal, with neighbors differing by exactly 1.

Terms

    a(0) =5a(1) =9a(2) =16a(3) =35a(4) =78a(5) =210a(6) =551a(7) =1569a(8) =4475a(9) =13078a(10) =38465a(11) =114584a(12) =343026a(13) =1034471a(14) =3134135a(15) =9540969a(16) =29154478a(17) =89407073a(18) =275016292a(19) =848329872a(20) =2623322133a(21) =8130714643a(22) =25252366057a(23) =78577560856a(24) =244933963301a(25) =764707458720

External references