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A207979
Number of n X 3 nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to any diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).
2
5, 67, 4192, 587208, 147512732, 58668937932, 34119101220224, 27451586022436696, 29334574202437277520, 40343697156563884675488, 69646199705725564208484736, 147875840329637502384856552096, 379682313150983568999164195148800
OFFSET
1,1
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..190 (terms 1..16 from R. H. Hardin)
EXAMPLE
Some solutions for n=4
..0..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..0....0..1..0
..1..1..1....1..1..1....1..2..1....1..1..2....1..1..1....1..2..1....2..1..0
..0..2..2....2..0..2....1..2..0....2..0..0....0..2..0....0..0..0....0..1..3
..1..1..0....1..0..1....0..2..0....3..1..4....1..1..0....2..1..1....0..4..0
CROSSREFS
Column 3 of A207981.
Sequence in context: A291807 A197776 A197606 * A129963 A115764 A252794
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 22 2012
STATUS
approved