A186878 Number of (n+2)X8 0..3 arrays with every 3X3 subblock commuting with each horizontal and vertical neighbor 3X3 subblock

186096, 18517, 32992, 108640, 230224, 287368, 338176, 414184, 568744, 927136, 1492600, 2387392, 4046104, 6975931, 11357422, 19105849, 32364013, 52661545, 88036021, 148729189, 243684934, 407116792, 686279218, 1129121971, 1883516491

Offset

1,1

Comments

Column 6 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>14

Example

Some solutions for 4X8
..0..0..0..0..2..0..0..2....0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0
..0..0..0..0..0..2..0..0....0..0..0..0..0..0..0..1....2..0..0..0..0..0..0..0
..2..0..0..0..0..0..2..0....1..0..0..0..0..0..0..0....2..2..0..0..0..0..0..0
..0..0..0..0..0..0..0..2....3..0..0..0..0..0..0..0....3..2..2..0..0..0..0..1

Crossrefs

Sequence in context: A032748 A180099 A092013 * A192103 A203442 A216901

Adjacent sequences: A186875 A186876 A186877 * A186879 A186880 A186881

Keyword

nonn

Author

R. H. Hardin Feb 28 2011

Status

approved