A201886 Number of zero-sum nX3 -2..2 arrays with every element equal to at least one horizontal or vertical neighbor

1, 63, 765, 26003, 559115, 16513425, 435630965, 12576072219, 355197660509, 10318921933459, 299385686951737, 8776646594694357, 257891661687979323, 7614010950576116449, 225337048658653360699, 6687122593012508859001

Offset

1,2

Comments

Column 3 of A201888

Links

R. H. Hardin, Table of n, a(n) for n = 1..32

Example

Some solutions for n=4
..2.-2.-1....2..2.-2...-1.-1.-1....1..1.-1....1..2..0....1.-2.-2....2.-1..2
..2.-2.-1...-1.-1.-2....2..0..0...-1..0.-1....1..2..0....1..1.-2....2.-1..2
.-1..0..0...-1..1..1....2..2..0...-1..0..2...-2.-2..0....1..0..1...-2.-1..0
.-1..2..2...-1..1..1...-1.-1.-1...-1.-1..2...-1.-1..0....0..0..1...-2.-1..0

Crossrefs

Sequence in context: A024004 A284927 A321545 * A232794 A091027 A112494

Adjacent sequences: A201883 A201884 A201885 * A201887 A201888 A201889

Keyword

nonn

Author

R. H. Hardin Dec 06 2011

Status

approved