The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A208986 Number of n-bead necklaces labeled with numbers -1..1 not allowing reversal, with sum zero and first differences in -1..1. 1
 1, 1, 1, 2, 3, 5, 9, 18, 35, 73, 151, 324, 691, 1503, 3277, 7212, 15927, 35407, 78967, 176942, 397717, 897079, 2029071, 4602438, 10464647, 23849545, 54468627, 124646180, 285762575, 656268311, 1509570433, 3477615648, 8022765075 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Column 1 of A208993. LINKS R. H. Hardin, Table of n, a(n) for n = 1..35 EXAMPLE All solutions for n=7: ..0...-1...-1...-1...-1...-1...-1...-1...-1 ..0...-1...-1...-1....0....0....0....0....0 ..0....0....0....0....0....0....0....1...-1 ..0....1....1....0....0....0....1....0....0 ..0....1....0....1....1....0....0....0....1 ..0....0....1....1....0....1....0....0....1 ..0....0....0....0....0....0....0....0....0 CROSSREFS Sequence in context: A047031 A056766 A262450 * A080091 A000602 A034790 Adjacent sequences:  A208983 A208984 A208985 * A208987 A208988 A208989 KEYWORD nonn AUTHOR R. H. Hardin, Mar 04 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 28 07:00 EDT 2022. Contains 354112 sequences. (Running on oeis4.)