A223120 Number of n X 2 0..2 arrays with no more than floor(nX2/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order.

1, 10, 72, 664, 5376, 47968, 406400, 3585408, 30987264, 272565760, 2378450944, 20921604096, 183506403328, 1615798558720, 14215745994752, 125323120574464, 1104802314190848, 9750937675890688, 86084069811027968, 760548158573379584

Offset

1,2

Comments

Column 2 of A223126.

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

Crossrefs

Cf. A223126.

Sequence in context: A155606 A181671 A058111 * A240275 A181402 A003366

Adjacent sequences: A223117 A223118 A223119 * A223121 A223122 A223123

Keyword

nonn

Author

R. H. Hardin, Mar 15 2013

Status

approved