A186595 Number of (n+3) X 8 0..3 arrays with every 4 X 4 subblock commuting with each horizontal and vertical neighbor 4 X 4 subblock.

21993587, 444066, 1398069, 5080629, 11494293, 12478581, 12563805, 12653493, 12809421, 13255797, 15722997, 19992861, 36147621, 56126589, 101158704, 151867875, 238699518, 338342913, 520547349, 732592545, 1101469437, 1568718489

Offset

1,1

Comments

Column 5 of A186599.

Links

R. H. Hardin, Table of n, a(n) for n = 1..44

Formula

Empirical: a(n)=2*a(n-1)-a(n-2)+3*a(n-4)-6*a(n-5)+3*a(n-6)+3*a(n-8)-3*a(n-9) for n>15.

Example

Some solutions for 5 X 8:
..2..0..0..0..0..2..3..3....0..0..0..0..0..0..0..2....1..0..0..0..0..0..0..3
..0..0..0..0..0..0..0..2....0..0..0..0..0..0..0..3....0..0..0..0..0..0..0..0
..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..3
..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0
..0..0..0..0..0..0..0..0....0..0..2..0..0..0..0..0....0..2..3..0..0..0..0..0

Crossrefs

Sequence in context: A210389 A364435 A118860 * A210076 A184375 A183799

Adjacent sequences: A186592 A186593 A186594 * A186596 A186597 A186598

Keyword

nonn

Author

R. H. Hardin, Feb 24 2011

Status

approved