A233171 Number of n X 5 0..5 arrays with no element x(i,j) adjacent to itself or value 5-x(i,j) horizontally, diagonally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order (unlabeled 6-colorings with no clashing color pairs).

36, 8576, 2469888, 736362496, 221463445504, 66799223701504, 20170789919653888, 6093499625887498240, 1841146791439003287552, 556341623248212690206720, 168115390615337809829953536, 50801739257391729644354404352

Offset: 1

Author

R. H. Hardin, Dec 05 2013

Keywords

• nonn

Examples

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

Links

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

Crossrefs

Column 5 of A233174.

Formula

Empirical: a(n) = 480*a(n-1) -60416*a(n-2) +1966080*a(n-3) [phone]*a(n-4) -1845493760*a(n-5) [phone]*a(n-6) -68719476736*a(n-7)