A186483 Number of (n+1)X(n+1) 0..4 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors

625, 839, 17015, 64680, 575344, 1759744, 15145144, 52024944, 422063944, 1535037344, 11681382744, 44716060144, 324000643944, 1297964842944, 9013961908344, 37548525033744, 251396274363144, 1083126105726944

Offset

1,1

Comments

Diagonal of A186484

Links

Table of n, a(n) for n=1..18.

Example

Some solutions for 3X3
..1..2..1....3..0..2....4..0..0....3..3..0....4..1..0....1..4..0....1..1..0
..2..1..2....0..3..0....4..0..0....4..0..3....0..0..1....2..0..4....3..0..1
..1..2..1....0..0..3....0..4..4....0..4..4....0..0..3....0..2..0....0..3..4

Crossrefs

Sequence in context: A210115 A186484 A184037 * A043352 A223183 A171995

Adjacent sequences: A186480 A186481 A186482 * A186484 A186485 A186486

Keyword

nonn

Author

R. H. Hardin Feb 22 2011

Status

approved