A230818 Number of nX7 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero

0, 18, 2114, 108006, 10872238, 888633610, 75341251814, 6484756891722, 546028214903014

Offset

1,2

Comments

Column 7 of A230819

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for n=4
..0..2..1..0..1..0..2....0..2..1..0..2..0..1....0..2..1..0..0..2..1
..1..1..0..2..2..0..1....1..2..0..1..1..0..2....1..0..2..2..1..2..0
..2..0..1..1..2..0..1....2..0..1..2..0..0..1....2..2..1..0..2..1..1
..0..1..2..0..1..0..2....1..0..2..0..1..2..0....0..1..2..0..1..0..2

Crossrefs

Sequence in context: A068181 A296614 A341842 * A276017 A178630 A136834

Adjacent sequences: A230815 A230816 A230817 * A230819 A230820 A230821

Keyword

nonn

Author

R. H. Hardin, Oct 30 2013

Status

approved