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A199825
Number of -1..1 arrays x(0..n+1) of n+2 elements with zero sum and no two neighbors summing to zero
1
2, 4, 4, 10, 22, 34, 66, 138, 250, 472, 944, 1806, 3450, 6772, 13172, 25478, 49794, 97348, 189772, 371246, 727506, 1424586, 2793034, 5483342, 10766950, 21154424, 41599648, 81840866, 161080918, 317230034, 625030514, 1231964394, 2429323642
OFFSET
1,1
COMMENTS
Column 1 of A199832
LINKS
EXAMPLE
All solutions for n=3
.-1....0....0....1
.-1....1...-1....1
..0....0....0....0
..1...-1....1...-1
..1....0....0...-1
CROSSREFS
Sequence in context: A193852 A327544 A202076 * A121049 A056415 A242993
KEYWORD
nonn
AUTHOR
R. H. Hardin Nov 11 2011
STATUS
approved