A186463 Number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock commuting with each of its horizontal and vertical 2X2 subblock neighbors

81, 129, 942, 3186, 13278, 34314, 136086, 399018, 1537038, 4607034, 16888062, 51777498, 185254926, 580089834, 2037893214, 6478793466, 22450788942, 72203998026, 247694103486, 803564559834, 2735884703406, 8933648141802

Offset

1,1

Comments

Diagonal of A186472

Links

R. H. Hardin, Table of n, a(n) for n = 1..23

Example

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

Crossrefs

Sequence in context: A053887 A119943 A001245 * A371846 A046317 A046374

Adjacent sequences: A186460 A186461 A186462 * A186464 A186465 A186466

Keyword

nonn

Author

R. H. Hardin Feb 22 2011

Status

approved