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A209035 Number of 7-bead necklaces labeled with numbers -n..n allowing reversal, with sum zero and first differences in -n..n. 1
6, 86, 576, 2517, 8235, 22249, 52208, 110285, 214440, 390344, 672932, 1108883, 1758433, 2698447, 4024458, 5854361, 8330650, 11624758, 15939472, 21513945, 28626249, 37599103, 48802532, 62660333, 79652814, 100324030, 125284570 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Row 7 of A209032.
LINKS
FORMULA
Empirical: a(n) = a(n-1) + a(n-2) - a(n-5) - a(n-7) - a(n-8) + a(n-10) + a(n-11) + 2*a(n-12) - 2*a(n-16) - a(n-17) - a(n-18) + a(n-20) + a(n-21) + a(n-23) - a(n-26) - a(n-27) + a(n-28).
EXAMPLE
Some solutions for n=6:
-5 -4 -5 -4 -2 -4 -3 -3 -5 -4 -3 -3 -3 -2 -6 -3
-2 -3 -4 -1 0 1 -1 -2 0 -2 2 1 2 -1 -5 -2
0 3 -1 0 1 -1 1 1 -2 -3 -1 1 -2 1 -1 3
1 3 2 5 -2 2 1 2 3 0 -1 -2 3 -2 1 1
4 0 4 1 1 1 2 1 0 5 -2 -2 -1 -1 5 -1
4 2 3 -2 1 -1 1 3 3 4 3 3 -2 5 6 0
-2 -1 1 1 1 2 -1 -2 1 0 2 2 3 0 0 2
CROSSREFS
Sequence in context: A187740 A332407 A358297 * A230782 A318042 A155654
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 04 2012
STATUS
approved

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Last modified April 23 22:36 EDT 2024. Contains 371917 sequences. (Running on oeis4.)