A269477 - OEIS

A269477

Number of nX2 arrays containing 2 copies of 0..n-1 avoiding the pattern down-up in every row and equal-up in every column.

1, 6, 54, 600, 9102, 188472, 5118012, 172101936, 6887210886, 321643938456

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OFFSET

1,2

COMMENTS

Column 2 of A269479.

LINKS

EXAMPLE

Some solutions for n=4

..1..0. .2..1. .2..1. .2..3. .2..1. .1..1. .3..0. .0..2. .3..0. .3..1

..2..2. .3..0. .0..1. .3..1. .2..1. .2..0. .1..3. .3..3. .3..2. .2..0

..3..3. .2..0. .0..2. .2..1. .3..0. .2..0. .1..2. .2..1. .1..2. .2..0

..1..0. .1..3. .3..3. .0..0. .3..0. .3..3. .0..2. .1..0. .0..1. .3..1

CROSSREFS

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 27 2016

STATUS

approved