A194539 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 one horizontal or vertical neighbor

1, 4, 132, 68106, 703256449, 108504879480483, 153378412416345530447

Offset

1,2

Comments

Column 7 of A194540

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for 3X3
..0......0......0......0......0......0......0......0......0......0......0
..1.1....1.1....1.0....1.2....0.1....1.2....1.2....1.2....0.1....1.2....1.2
..2.2.0..0.2.0..0.2.3..1.3.3..2.3.1..0.3.4..1.3.2..2.0.3..2.2.1..0.3.2..0.1.2

Crossrefs

Sequence in context: A204077 A194537 A194538 * A146547 A274703 A045482

Adjacent sequences: A194536 A194537 A194538 * A194540 A194541 A194542

Keyword

nonn

Author

R. H. Hardin Aug 28 2011

Status

approved