A183817 1/81 the number of (n+1)X7 0..2 arrays with no 2X2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor

32768, 26630220, 20864057480, 16607782066704, 13143529051807800, 10425296660739253420

Offset

1,1

Comments

Column 6 of A183819

Links

Table of n, a(n) for n=1..6.

Example

Some solutions with upper left block zero for 3X7
..0..0..0..0..0..2..1....0..0..0..0..2..0..1....0..0..0..0..2..2..0
..0..0..2..2..1..1..1....0..0..1..1..0..0..1....0..0..2..2..2..2..1
..1..0..1..0..2..1..0....2..0..2..0..1..1..0....1..0..2..0..1..1..0

Crossrefs

Sequence in context: A017694 A010803 A236223 * A303267 A323545 A017693

Adjacent sequences: A183814 A183815 A183816 * A183818 A183819 A183820

Keyword

nonn

Author

R. H. Hardin Jan 07 2011

Status

approved