A186586 Number of (n+3)X9 0..2 arrays with every 4X4 subblock commuting with each horizontal and vertical neighbor 4X4 subblock

1728546, 79015, 149305, 328891, 626233, 811795, 823249, 841075, 880969, 1019683, 1221265, 1504507, 2353993, 3537235, 4869121, 7110411, 10563977, 14962483, 20061441, 27545691, 39153465, 55017603, 74946417, 104128395, 148464553

Offset

1,1

Comments

Column 6 of A186589

Links

R. H. Hardin, Table of n, a(n) for n = 1..78

Formula

Empirical: a(n)=2*a(n-1)-a(n-2)+2*a(n-4)-4*a(n-5)+2*a(n-6)+2*a(n-8)-2*a(n-9) for n>16

Example

Some solutions for 5X9
..0..0..0..0..0..0..0..2..0....0..0..0..0..0..0..2..0..1
..0..0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0..2
..2..0..0..0..0..0..0..0..2....1..0..0..0..0..0..0..0..0
..1..0..0..0..0..0..0..0..0....0..1..0..0..0..0..0..0..0
..1..1..0..0..0..0..0..0..0....2..0..1..0..0..0..0..0..0

Crossrefs

Sequence in context: A083646 A157858 A157862 * A131639 A187139 A185844

Adjacent sequences: A186583 A186584 A186585 * A186587 A186588 A186589

Keyword

nonn

Author

R. H. Hardin Feb 24 2011

Status

approved