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).

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

Adjacent sequences: A207976 A207977 A207978 * A207980 A207981 A207982

Keyword

nonn

Author

R. H. Hardin, Feb 22 2012

Status

approved