A208307 Number of 7 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, 877, 27644437, 27700815674032, 196551307092757144384, 5737167377815628378510929822, 510275358863420934339418249390485008, 114130286115375064054502412158789812265958284, 56140177561453730943968268473396800731088097525712216

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..50

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..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..1....0..1..2..0....0..1..0..1....0..1..0..1
..2..1..0..1....0..1..0..1....0..1..2..0....0..1..0..1....0..1..0..1
..0..1..2..0....0..1..0..1....0..1..2..0....0..1..0..1....0..1..0..1
..0..1..2..1....2..1..0..1....0..1..2..0....0..1..0..1....0..2..0..1
..0..1..0..1....0..1..0..1....0..1..2..0....0..1..0..1....0..1..0..1

Crossrefs

Row 7 of A208301.

Sequence in context: A188391 A209464 A209526 * A208787 A208587 A208472

Adjacent sequences: A208304 A208305 A208306 * A208308 A208309 A208310

Keyword

nonn

Author

R. H. Hardin Feb 25 2012

Extensions

a(0)=1 prepended and terms a(6) and beyond from Andrew Howroyd, May 18 2020

Status

approved