A194534 Number of lower triangles of an n X n 0..2 array with new values introduced in row major order 0..2 and no element equal to more than one horizontal or vertical neighbor

1, 4, 59, 1851, 119548, 16039294, 4460214471, 2572187445993, 3075932897564028, 7627704068111688574, 39223874584658826539499, 418261269510360187893175534, 9248796169262343437995449320699, 424095060368117191810477243815045914

Offset

1,2

Comments

Column 2 of A194540

Links

Table of n, a(n) for n=1..14.

Example

Some solutions for 3X3
..0......0......0......0......0......0......0......0......0......0......0
..0.1....0.1....1.2....1.1....1.2....1.1....1.1....1.2....1.1....1.0....1.1
..2.0.0..1.0.0..0.2.0..2.0.0..2.1.2..0.2.1..2.2.1..0.1.0..2.0.2..1.2.0..0.2.0

Crossrefs

Sequence in context: A198508 A126754 A264820 * A331712 A026586 A298064

Adjacent sequences: A194531 A194532 A194533 * A194535 A194536 A194537

Keyword

nonn

Author

R. H. Hardin Aug 28 2011

Status

approved