A186880 Number of (n+2)X10 0..3 arrays with every 3X3 subblock commuting with each horizontal and vertical neighbor 3X3 subblock

322910, 25381, 46624, 148048, 310528, 414184, 571984, 801208, 1130584, 1842208, 3014488, 4813744, 8147608, 13457800, 21637048, 37154419, 62117614, 101085745, 172069837, 287321977, 469126669, 793531357, 1325629774, 2174290240

Offset

1,1

Comments

Column 8 of A186881

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=2*a(n-1)-a(n-2)+3*a(n-3)-6*a(n-4)+3*a(n-5)+3*a(n-6)-3*a(n-7) for n>16

Example

Some solutions for 4X10
..0..0..3..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0..3..0
..1..0..0..3..0..0..0..0..0..1....0..0..0..0..0..0..0..0..0..0
..0..1..0..0..3..0..0..0..0..1....2..0..0..0..0..0..0..0..0..0
..0..0..1..0..0..3..0..0..0..1....3..3..0..0..0..0..0..0..0..2

Crossrefs

Sequence in context: A097937 A244565 A362874 * A114667 A233978 A375264

Adjacent sequences: A186877 A186878 A186879 * A186881 A186882 A186883

Keyword

nonn

Author

R. H. Hardin Feb 28 2011

Status

approved