A233259 Number of 4 X n 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabelled 6-colorings with no clashing color pairs).

48, 2080, 221696, 23896064, 2647261184, 294517735424, 32835998056448, 3662495243829248, 408547159030366208, 45573786789742641152, 5083813692357704941568, 567106285442412421578752

Offset: 1

Author

R. H. Hardin, Dec 06 2013

Keywords

• nonn

Comments

Row 4 of A233256.

Examples

			Some solutions for n=3
..0..1..2....0..1..2....0..1..2....0..1..0....0..1..2....0..1..0....0..1..0
..2..1..0....0..4..3....0..4..0....0..2..4....2..4..3....2..1..3....5..2..1
..5..2..5....0..1..0....0..1..5....4..3..1....2..0..4....2..5..3....4..3..1
..0..2..1....2..1..5....0..3..1....4..5..4....3..0..4....2..1..5....4..2..5
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A233256.

Formula

Empirical: a(n) = 160*a(n-1) -6144*a(n-2) +86016*a(n-3) -393216*a(n-4) for n>8.