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A207866
Number of n X 4 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any horizontal or vertical neighbor (colorings ignoring permutations of colors).
2
5, 500, 278982, 455546040, 1625686993918, 10764437129618296, 119010390034543491042, 2040368351234509987725212, 51350903376256822436382238230, 1818472780230512625778385363238944, 87604972777997602798029710458933219862, 5585379463993456459896660751935863285859008
OFFSET
1,1
LINKS
EXAMPLE
Some solutions for n=5
..0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1....0..1..0..1
..1..0..1..0....1..0..1..0....1..2..3..2....1..0..1..0....1..2..1..0
..0..1..0..1....0..1..2..1....0..1..0..1....0..1..2..1....0..1..0..1
..1..2..1..0....1..0..1..0....1..0..1..0....1..0..1..0....1..2..1..0
..0..1..0..1....0..1..3..1....0..1..0..1....0..1..0..1....0..1..2..1
CROSSREFS
Column 4 of A207868.
Sequence in context: A124358 A198719 A198910 * A013305 A114066 A014287
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 21 2012
EXTENSIONS
Terms a(11) and beyond from Andrew Howroyd, Mar 11 2023
STATUS
approved