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A203456 Number of nX4 0..2 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors 1
1, 22, 543, 8837, 143936, 2527020, 44974778, 799146435, 14222292590, 253497958735, 4520112095307, 80604855648245, 1437506215952323, 25637856292628890, 457259186435170066, 8155419408921364692 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A203460

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Sequence in context: A266884 A182610 A320766 * A271266 A333899 A239652

Adjacent sequences:  A203453 A203454 A203455 * A203457 A203458 A203459

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 02 2012

STATUS

approved

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Last modified September 26 06:16 EDT 2021. Contains 347664 sequences. (Running on oeis4.)