A194537 Number of lower triangles of an n X n 0..5 array with new values introduced in row major order 0..5 and no element equal to more than one horizontal or vertical neighbor

1, 4, 132, 62038, 286773762, 8096809998526, 1243336605965267360, 1026437889413641002431445

Offset

1,2

Comments

Column 5 of A194540

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
..1.2....1.2....1.2....1.2....1.2....1.2....0.1....1.0....1.1....0.1....0.1
..2.0.3..0.2.1..3.1.1..3.2.1..3.0.1..3.4.1..1.0.1..2.0.1..0.0.2..1.0.2..1.0.0

Crossrefs

Sequence in context: A192837 A338040 A204077 * A194538 A194539 A146547

Adjacent sequences: A194534 A194535 A194536 * A194538 A194539 A194540

Keyword

nonn

Author

R. H. Hardin Aug 28 2011

Status

approved