A200424 - OEIS

A200424

Number of -2..2 arrays x(0..n+2) of n+3 elements with zero sum and no two or three adjacent elements summing to zero

20, 80, 212, 594, 1928, 6780, 23674, 80750, 271000, 909282, 3082640, 10545846, 36174576, 123964062, 424595930, 1456168762, 5004245744, 17226485764, 59361633214, 204702938074, 706403203606, 2439664629760, 8432567247356

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OFFSET

1,1

COMMENTS

Column 2 of A200430

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

EXAMPLE

Some solutions for n=3

.-2....2...-1...-1....2...-2....0...-1....2....2....2...-1....1...-1....1....0

.-2...-1....0...-2....1...-2...-1...-2...-1....1....1....0....2....0....0...-1

..0...-2....2....0...-2....1....2...-2....2....0....0...-2....1...-2...-2....0

..1...-2....0....1....0....2....1....1....0...-2...-2...-1...-2....0...-2...-2

..2....1....1....1...-1....0....0....2...-1...-2....0....2...-1....1....1....1

..1....2...-2....1....0....1...-2....2...-2....1...-1....2...-1....2....2....2

CROSSREFS

Sequence in context: A337988 A002609 A195322 * A211463 A244449 A041776

Adjacent sequences: A200421 A200422 A200423 * A200425 A200426 A200427

KEYWORD

nonn

AUTHOR

R. H. Hardin Nov 17 2011

STATUS

approved