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!)
 A209066 Number of n-bead necklaces labeled with numbers -1..1 not allowing reversal, with sum zero and avoiding the pattern z z+1 z+2. 1
 1, 2, 2, 5, 8, 19, 39, 95, 223, 554, 1373, 3493, 8906, 23016, 59805, 156588, 412082, 1090443, 2897828, 7733433, 20712345, 55661171, 150031505, 405533996, 1098949141, 2985066757, 8125987470, 22165517960, 60575472281, 165835969094 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 1 of A209073. LINKS R. H. Hardin, Table of n, a(n) for n = 1..33 EXAMPLE Some solutions for n=6: .-1...-1...-1...-1....0...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1...-1 ..1....0...-1...-1....0...-1....0....1....0...-1....1....0....1....0...-1....0 ..0...-1....1....1....0....0....0...-1...-1....1....0....0...-1....0....1....0 .-1....1....0...-1....0....0....1....1....1....0....0....0....1....1....1...-1 ..1....0....0....1....0....1...-1...-1....1....1....0....1....0....0...-1....1 ..0....1....1....1....0....1....1....1....0....0....0....0....0....0....1....1 CROSSREFS Sequence in context: A052531 A257517 A095005 * A208938 A019086 A076949 Adjacent sequences:  A209063 A209064 A209065 * A209067 A209068 A209069 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 27 21:52 EDT 2020. Contains 334671 sequences. (Running on oeis4.)