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A267899 Number of nX3 arrays containing 3 copies of 0..n-1 with every element equal to at least one horizontal or vertical neighbor and the top left element equal to 0. 0
1, 3, 20, 138, 1488, 20400, 317520, 5911920, 126080640, 2999566080, 79604985600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A267901.

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A267901.

Sequence in context: A056298 A114479 A074574 * A073514 A163065 A082143

Adjacent sequences:  A267896 A267897 A267898 * A267900 A267901 A267902

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 22 2016

STATUS

approved

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Last modified December 6 18:03 EST 2019. Contains 329809 sequences. (Running on oeis4.)