A209011 Number of 7-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and first and second differences in -n..n.

3, 23, 157, 703, 2313, 6261, 14701, 31069, 60429, 109991, 189627, 312461, 495497, 760323, 1133925, 1649437, 2347063, 3275011, 4490479, 6060743, 8064195, 10591639, 13747397, 17650689, 22436937, 28259205, 35289631, 43720971, 53768203, 65670121

Offset

1,1

Comments

Row 7 of A209007.

Links

R. H. Hardin, Table of n, a(n) for n = 1..79

Example

Some solutions for n=6:
  -3  -1  -3  -4  -5  -4  -5  -5  -4  -5  -4  -4  -3  -2  -3  -6
  -1  -1   0  -3  -2  -2  -5  -5  -1  -1  -3  -2  -2  -1  -1  -1
   2  -1   1  -2   3  -2   0   1   0   2  -2   0  -1   1  -2   4
   0  -1   4   3   2   3   4   4   4   0   2   1   1   3   1   4
   2   3   1   4   4   3   4   4   2   4   2   2   3   0   3   4
   1   1  -1   4   1   2   3   1   1   3   4   3   2   0   2   0
  -1   0  -2  -2  -3   0  -1   0  -2  -3   1   0   0  -1   0  -5

Crossrefs

Sequence in context: A264461 A006184 A308677 * A164536 A037789 A037670

Adjacent sequences: A209008 A209009 A209010 * A209012 A209013 A209014

Keyword

nonn

Author

R. H. Hardin, Mar 04 2012

Status

approved