A222502 Number of 3Xn 0..3 arrays with exactly floor(3Xn/2) elements unequal to at least one horizontal, diagonal or antidiagonal neighbor, with new values introduced in row major 0..3 order

0, 4, 6, 35, 81, 1758, 3964, 114039, 249121, 7654526, 17528506, 521272961, 1262530701, 35686911158, 90924250112, 2450312511955, 6543156266427, 168629675723808, 470547135992104

Offset

1,2

Comments

Row 3 of A222500

Links

Table of n, a(n) for n=1..19.

Example

Some solutions for n=4
..0..1..0..2....0..1..1..1....0..1..2..1....0..0..0..0....0..1..0..1
..0..0..0..0....0..1..1..1....1..1..1..1....0..0..0..0....1..1..1..1
..0..0..0..0....0..1..1..1....1..1..1..1....0..1..0..1....1..1..1..1

Crossrefs

Sequence in context: A137021 A176002 A175061 * A092187 A092765 A056315

Adjacent sequences: A222499 A222500 A222501 * A222503 A222504 A222505

Keyword

nonn

Author

R. H. Hardin Feb 23 2013

Status

approved