A203456 Number of nX4 0..2 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors

1, 22, 543, 8837, 143936, 2527020, 44974778, 799146435, 14222292590, 253497958735, 4520112095307, 80604855648245, 1437506215952323, 25637856292628890, 457259186435170066, 8155419408921364692

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