A199193 Number of n X n 0..3 arrays with values 0..3 introduced in row major order, the number of instances of each value within one of each other, and every element equal to zero or two horizontal or vertical neighbors.

1, 1, 114, 11734, 86954982, 329877369234

Offset

1,3

Comments

Diagonal of A199201.

Links

Table of n, a(n) for n=1..6.

Example

Some solutions for n=4
..0..1..2..1....0..1..0..2....0..1..0..2....0..1..0..1....0..1..2..0
..3..2..0..2....2..3..2..0....2..0..3..1....1..2..3..0....3..2..1..3
..0..1..3..0....3..1..3..1....3..1..2..0....2..3..0..3....0..1..3..1
..2..3..1..3....2..0..1..3....2..3..1..3....3..2..1..2....2..0..2..3

Crossrefs

Cf. A199201.

Sequence in context: A112485 A220685 A199249 * A188694 A188507 A189616

Adjacent sequences: A199190 A199191 A199192 * A199194 A199195 A199196

Keyword

nonn

Author

R. H. Hardin, Nov 03 2011

Status

approved