This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A208725 #9 Mar 19 2017 01:12:10
%S A208725 5,9,16,35,78,210,551,1569,4475,13078,38465,114584,343026,1034471,
%T A208725 3134135,9540969,29154478,89407073,275016292,848329872,2623322133,
%U A208725 8130714643,25252366057,78577560856,244933963301,764707458720,2391026407058,7486342546939
%N A208725 Number of 2n-bead necklaces labeled with numbers 1..6 not allowing reversal, with neighbors differing by exactly 1.
%H A208725 Andrew Howroyd, <a href="/A208725/b208725.txt">Table of n, a(n) for n = 1..100</a>
%F A208725 a(n) = (1/n) * Sum_{d | n} totient(n/d) * A198636(d). - _Andrew Howroyd_, Mar 18 2017
%e A208725 All solutions for n=3:
%e A208725 ..3....2....1....3....5....2....4....1....2....3....4....4....1....2....1....3
%e A208725 ..4....3....2....4....6....3....5....2....3....4....5....5....2....3....2....4
%e A208725 ..5....4....3....5....5....2....6....1....4....3....4....4....3....2....1....3
%e A208725 ..4....3....4....6....6....3....5....2....5....4....5....5....2....3....2....4
%e A208725 ..5....4....3....5....5....2....6....1....4....5....4....6....3....4....3....3
%e A208725 ..4....3....2....4....6....3....5....2....3....4....5....5....2....3....2....4
%Y A208725 Column 6 of A208727.
%K A208725 nonn
%O A208725 1,1
%A A208725 _R. H. Hardin_, Mar 01 2012
%E A208725 a(17)-a(28) from _Andrew Howroyd_, Mar 18 2017