A194572 Number of lower triangles of an n X n 0..4 array with new values introduced in row major order 0..4 and no element equal to more than two horizontal or vertical neighbors

1, 5, 193, 80780, 225623340, 3211386454648, 223665935176544829, 76009506543180381646618, 126023279808505699474721273930, 1019406708191445081689134021299430885

Offset

1,2

Comments

Column 4 of A194576

Links

Table of n, a(n) for n=1..10.

Example

Some solutions for 3X3
..0......0......0......0......0......0......0......0......0......0......0
..1.2....1.2....1.1....1.2....1.0....1.1....1.2....1.0....0.1....1.2....1.2
..1.3.1..3.2.2..2.2.1..3.2.0..2.0.2..2.1.3..1.0.1..0.1.1..2.1.1..0.1.3..3.1.2

Crossrefs

Sequence in context: A198482 A198523 A093154 * A068793 A194573 A194574

Adjacent sequences: A194569 A194570 A194571 * A194573 A194574 A194575

Keyword

nonn

Author

R. H. Hardin Aug 29 2011

Status

approved