A194575 Number of lower triangles of an n X n 0..7 array with new values introduced in row major order 0..7 and no element equal to more than two horizontal or vertical neighbors

1, 5, 194, 110064, 1237399743, 230795314260831, 443383367826271457152, 7112925826561472131385895933

Offset

1,2

Comments

Column 7 of A194576

Links

Table of n, a(n) for n=1..8.

Example

Some solutions for 3X3
..0......0......0......0......0......0......0......0......0......0......0
..0.0....1.0....0.1....1.2....1.0....1.2....0.1....0.0....0.1....0.1....1.2
..1.1.1..2.2.0..2.2.1..1.1.0..1.1.2..1.1.2..2.3.1..1.2.0..0.1.2..1.0.1..2.2.1

Crossrefs

Sequence in context: A068793 A194573 A194574 * A240772 A142927 A114351

Adjacent sequences: A194572 A194573 A194574 * A194576 A194577 A194578

Keyword

nonn

Author

R. H. Hardin Aug 29 2011

Status

approved