|
|
A208304
|
|
Number of 4 X n nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal or antidiagonal neighbor (colorings ignoring permutations of colors).
|
|
1
|
|
|
1, 15, 877, 433252, 656404264, 2227156082842, 14216420563705724, 152834703739876070716, 2562708954761302163168116, 63338792205478132108785337770, 2209363673047740561377241754826088, 105080298194482216982100203776114994146, 6626004995903793205763315247117544349120572
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
EXAMPLE
|
Some solutions for n=4:
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..0..1..2..0....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..2
..0..1..2..0....0..1..0..1....0..1..0..1....2..1..0..1....2..1..0..1
..0..1..2..0....2..1..0..1....0..1..0..1....0..1..0..1....0..1..0..2
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
a(0)=1 prepended and terms a(8) and beyond from Andrew Howroyd, May 18 2020
|
|
STATUS
|
approved
|
|
|
|