A267726 Number of 3Xn arrays containing n copies of 0..3-1 with every element equal to at least one horizontal neighbor and the top left element equal to 0.

0, 2, 2, 30, 58, 588, 2388, 17456, 102874, 731154, 5027962, 36610288, 266876496, 1982397806, 14796809106, 111298650288, 840466993090, 6372988144620, 48466708273020, 369602842446350, 2824995007935614, 21637397279211678

Offset

1,2

Comments

Row 3 of A267724.

Links

R. H. Hardin, Table of n, a(n) for n = 1..38

Example

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

Crossrefs

Cf. A267724.

Sequence in context: A359998 A343172 A276821 * A371562 A309191 A372305

Adjacent sequences: A267723 A267724 A267725 * A267727 A267728 A267729

Keyword

nonn

Author

R. H. Hardin, Jan 20 2016

Status

approved