Number of 2n-bead necklaces labeled with numbers 1..6 allowing reversal, with neighbors differing by exactly 1.

A208669

Number of 2n-bead necklaces labeled with numbers 1..6 allowing reversal, with neighbors differing by exactly 1.

Terms

    a(0) =5a(1) =9a(2) =16a(3) =32a(4) =65a(5) =152a(6) =360a(7) =937a(8) =2512a(9) =7034a(10) =20124a(11) =58899a(12) =174408a(13) =522453a(14) =1576468a(15) =4787425a(16) =14607763a(17) =44758541a(18) =137607258a(19) =424343533a(20) =1311982883a(21) =4065937220a(22) =12627227963a(23) =39290663343a(24) =122470374536a(25) =382359843141

External references