A222750 Number of 3Xn 0..3 arrays with exactly floor(3Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order

0, 20, 2438, 126947, 6363724, 390671426, 20825891902, 1302002871105, 68980846569683, 4414953646397182, 234735040362399277, 15230133968254421161, 811171016916133624250, 53158538404174454164168, 2835711932391664974150091

Offset

1,2

Comments

Row 3 of A222747

Links

R. H. Hardin, Table of n, a(n) for n = 1..22

Example

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

Crossrefs

Sequence in context: A329067 A064878 A222943 * A250019 A145405 A028458

Adjacent sequences: A222747 A222748 A222749 * A222751 A222752 A222753

Keyword

nonn

Author

R. H. Hardin Mar 04 2013

Status

approved