A208099 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, diagonal or antidiagonal neighbor (colorings ignoring permutations of colors).

1, 15, 500, 192328, 235862938, 677352910013, 3773408294000427, 36179066767453804155, 549736601190850705047301, 12463226118187748082979153202, 402612019211536786633308878052340, 17870804510325656079748707416649732732, 1058340866272922899343613575761029687845720

Offset: 0

Author

R. H. Hardin, Feb 23 2012

Keywords

• nonn

Examples

			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..2....0..1..0..1....2..1..0..1....2..1..0..1
..0..1..2..1....2..1..0..1....2..1..0..2....0..3..0..1....0..1..2..1
..0..1..3..1....0..1..0..2....0..1..0..1....4..1..0..1....0..1..0..1
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..100

Crossrefs

Row 4 of A208096.

Extensions

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