A194570 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 two horizontal or vertical neighbors

1, 5, 113, 7696, 1429748, 723276072, 996233663484, 3736289882783364, 38153100681294466800, 1060791108320009447746940, 80304497397124644777045379184, 16552355212984292716901267397576440

Offset

1,2

Comments

Column 2 of A194576

Links

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

Example

Some solutions for 3X3
..0......0......0......0......0......0......0......0......0......0......0
..1.1....1.2....1.0....0.1....1.2....0.0....0.1....1.1....1.2....1.1....1.0
..1.0.2..2.2.0..0.0.2..2.1.0..1.1.2..1.0.0..1.0.1..0.0.1..0.1.0..2.0.2..2.2.0

Crossrefs

Sequence in context: A009603 A009678 A009691 * A210908 A355074 A053712

Adjacent sequences: A194567 A194568 A194569 * A194571 A194572 A194573

Keyword

nonn

Author

R. H. Hardin Aug 29 2011

Status

approved