A194781 Number of lower triangles of a (2n+1)X(2n+1) 0..n array with new values introduced in row major order 0..n and no element unequal to more than one horizontal or vertical neighbor

6, 41, 265, 1736, 11857, 85007, 639753, 5045602, 41615156, 358185389, 3210667479, 29914284821, 289187621887

Offset

1,1

Comments

Row 3 of A194778

Links

Table of n, a(n) for n=1..13.

Example

Some solutions for n=2 containing a 2
..0..........0..........0..........0..........0..........0..........0
..1.1........1.1........1.1........0.0........1.1........1.1........0.1
..1.1.2......1.1.1......1.1.1......1.1.1......1.1.1......1.1.2......0.1.1
..1.1.2.2....1.1.1.1....1.1.1.2....1.1.1.1....2.2.2.2....1.1.2.2....0.1.1.1
..1.1.2.2.1..2.2.2.2.2..1.1.1.2.2..1.1.1.1.2..2.2.2.2.0..1.1.2.2.0..0.1.1.1.2

Crossrefs

Sequence in context: A198795 A320090 A266425 * A323969 A252980 A274997

Adjacent sequences: A194778 A194779 A194780 * A194782 A194783 A194784

Keyword

nonn

Author

R. H. Hardin Sep 02 2011

Status

approved