The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A208718 Number of n-bead necklaces labeled with numbers 1..5 allowing reversal, with no adjacent beads differing by more than 1. 1
 5, 9, 13, 24, 38, 78, 140, 306, 634, 1464, 3326, 8066, 19454, 48534, 121294, 308154, 785222, 2018548, 5203634, 13482426, 35019010, 91251438, 238278314, 623629333, 1635062126, 4294493670, 11296419934, 29757590061, 78489973742, 207281830814 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Andrew Howroyd, Table of n, a(n) for n = 1..100 FORMULA a(2n+1) = (1/2) * (A208774(2n+1) + r(n+1)) where r(n) = A057960(n+1). - Andrew Howroyd, Mar 03 2017 a(2n) = (1/2) * A208774(2n) + (1/4) * (r(n) + r(n+1)) where r(n) = A057960(n+1). - Andrew Howroyd, Mar 03 2017 EXAMPLE All solutions for n=3: ..3....1....2....4....5....1....2....2....3....4....1....4....3 ..3....1....2....5....5....1....3....2....4....4....2....4....3 ..4....1....2....5....5....2....3....3....4....5....2....4....3 CROSSREFS Column 5 of A208721. Cf. A208774, A057960. Sequence in context: A314796 A314797 A314798 * A208774 A271391 A151907 Adjacent sequences:  A208715 A208716 A208717 * A208719 A208720 A208721 KEYWORD nonn AUTHOR R. H. Hardin, Mar 01 2012 EXTENSIONS a(25)-a(30) from Andrew Howroyd, Mar 03 2017 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 8 14:52 EDT 2020. Contains 333314 sequences. (Running on oeis4.)