A222913 Number of nX2 0..2 arrays with exactly floor(nX2/2) elements equal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..2 order

0, 6, 18, 136, 654, 3972, 21778, 127226, 727214, 4237154, 24617576, 144049162, 843945398, 4961892900, 29226194746, 172530718840, 1020187713214, 6042341555988, 35837121558046, 212824919490178, 1265353059527832

Offset

1,2

Comments

Column 2 of A222918

Links

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

Example

Some solutions for n=3
..0..0....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1....0..1
..0..1....2..2....0..2....0..0....2..2....2..1....2..0....1..0....1..1....0..0
..2..0....1..2....0..1....2..1....2..1....0..1....2..2....1..2....0..2....1..2

Crossrefs

Sequence in context: A208822 A003496 A009582 * A091054 A012774 A306656

Adjacent sequences: A222910 A222911 A222912 * A222914 A222915 A222916

Keyword

nonn

Author

R. H. Hardin Mar 09 2013

Status

approved