A194783 Number of lower triangles of a (2n+3)X(2n+3) 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

23, 219, 1641, 11686, 84727, 639325, 5044981, 41614291, 358184223, 3210665949, 29914282858, 289187619416

Offset

1,1

Comments

Row 5 of A194778

Links

Table of n, a(n) for n=1..12.

Example

Some solutions for n=2 containing a 2
..0..............0..............0..............0..............0
..1.1............1.1............1.1............0.0............1.1
..1.1.2..........1.1.1..........1.1.1..........0.0.0..........1.1.1
..1.1.2.2........1.1.1.1........1.1.1.1........0.0.0.0........2.2.2.2
..1.1.2.2.2......1.1.1.1.1......1.1.1.1.1......0.0.0.0.1......2.2.2.2.1
..1.1.2.2.2.2....2.2.2.2.2.2....2.2.2.2.2.2....0.0.0.0.1.1....2.2.2.2.1.1
..1.1.2.2.2.2.2..2.2.2.2.2.2.2..2.2.2.2.2.2.1..0.0.0.0.1.1.2..2.2.2.2.1.1.0

Crossrefs

Sequence in context: A201831 A027481 A201211 * A254870 A110028 A117608

Adjacent sequences: A194780 A194781 A194782 * A194784 A194785 A194786

Keyword

nonn

Author

R. H. Hardin Sep 02 2011

Status

approved