A199090 Number of 2nX4 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 exactly one horizontal or vertical neighbor.

5, 420, 44837, 5471810, 726413391, 101787127746, 14800090575471, 2211229549716802, 337343474770282699, 52327061345761775192

Offset

1,1

Comments

Even terms of column 4 of A199092

Links

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

Example

Some solutions for 4X4
..0..1..2..3....0..1..2..2....0..1..2..0....0..0..1..0....0..1..2..2
..0..1..2..3....0..1..0..0....0..1..2..0....2..3..1..0....0..1..0..0
..3..3..0..1....2..2..3..3....3..3..1..1....2..3..2..2....3..2..1..3
..2..2..0..1....3..3..1..1....2..2..3..3....1..1..3..3....3..2..1..3

Crossrefs

Sequence in context: A218406 A217939 A147684 * A218393 A038003 A359992

Adjacent sequences: A199087 A199088 A199089 * A199091 A199092 A199093

Keyword

nonn

Author

R. H. Hardin, Nov 02 2011

Status

approved