This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A208671 T(n,k) = number of 2n-bead necklaces labeled with numbers 1..k allowing reversal, with neighbors differing by exactly 1. 7
 0, 1, 0, 2, 1, 0, 3, 3, 1, 0, 4, 5, 4, 1, 0, 5, 7, 8, 6, 1, 0, 6, 9, 12, 14, 8, 1, 0, 7, 11, 16, 23, 24, 13, 1, 0, 8, 13, 20, 32, 44, 47, 18, 1, 0, 9, 15, 24, 41, 65, 97, 89, 30, 1, 0, 10, 17, 28, 50, 86, 152, 212, 187, 46, 1, 0, 11, 19, 32, 59, 107, 208, 360, 512, 396, 78, 1, 0, 12, 21, 36 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Table starts .0.1..2...3...4...5....6....7....8....9...10..11..12..13.14.15.16 .0.1..3...5...7...9...11...13...15...17...19..21..23..25.27.29 .0.1..4...8..12..16...20...24...28...32...36..40..44..48.52 .0.1..6..14..23..32...41...50...59...68...77..86..95.104 .0.1..8..24..44..65...86..107..128..149..170.191.212 .0.1.13..47..97.152..208..264..320..376..432.488 .0.1.18..89.212.360..514..669..824..979.1134 .0.1.30.187.512.937.1398.1866.2335.2804 LINKS R. H. Hardin, Table of n, a(n) for n = 1..148 FORMULA T(n,k) = (2*A208727(n) + A220062(n+1,k))/4. - Andrew Howroyd, Mar 19 2017 EXAMPLE All solutions for n=4, k=3: ..1....1....1....1....1....2 ..2....2....2....2....2....3 ..3....1....1....1....3....2 ..2....2....2....2....2....3 ..1....3....1....1....3....2 ..2....2....2....2....2....3 ..3....3....3....1....3....2 ..2....2....2....2....2....3 CROSSREFS Column 3 is A000029. Cf. A208727, A220062. Sequence in context: A122202 A122285 A100224 * A208727 A242378 A268820 Adjacent sequences:  A208668 A208669 A208670 * A208672 A208673 A208674 KEYWORD nonn,tabl AUTHOR R. H. Hardin, Feb 29 2012 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 December 11 21:28 EST 2019. Contains 329937 sequences. (Running on oeis4.)