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A201999 Number of -1..1 circular arrays x(0..n+1) of n+2 elements with zero sums of x(i) and x(i)*x((i+1) mod (n+2)) 1
1, 9, 11, 43, 85, 329, 577, 1921, 4115, 14331, 32631, 106527, 262481, 833225, 2118711, 6523351, 17225857, 52322449, 141538657, 424472841, 1171251495, 3484084667, 9746606361, 28817241129, 81509487175, 240107776015, 684814280371 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 1 of A202006
LINKS
EXAMPLE
Some solutions for n=10
.-1....1....0...-1....0....0....1....0....1...-1....0....1....0....0...-1....0
..0...-1....1....0...-1...-1....0....1....1...-1...-1....0....1....1....0....1
..0...-1....1....1...-1....0....0...-1...-1....1....0....0...-1....0...-1....1
..1....0...-1...-1....0....0...-1....1...-1...-1....0...-1...-1....0...-1...-1
..0....0...-1....0....0....0....1....1....0....1....0...-1...-1...-1....0...-1
..0....0....0....1....0....1...-1....0....1....1....1....1....1...-1....1....0
.-1....0....0....1...-1....1...-1...-1...-1...-1....1....1...-1....0....0....1
.-1....0....0....0....1....0....0...-1...-1...-1...-1...-1....0....1...-1....0
..0....1....0....0....1...-1....0....1....1....0....0....0...-1....0....1...-1
..1....0...-1...-1...-1....1....0....1....0....1....0....0....1....0....0....0
..0....0....1....0....1....0....0...-1....0....1....0...-1....1....1....1...-1
..1....0....0....0....1...-1....1...-1....0....0....0....1....1...-1....1....1
CROSSREFS
Sequence in context: A145790 A345109 A143465 * A195309 A242507 A116152
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 07 2011
STATUS
approved

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)