A233199 Number of nX5 0..7 arrays with no element x(i,j) adjacent to itself or value 7-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 4 5 and 6, 2 appearing before 3 4 and 5, and 3 appearing before 4 in row major order (unlabelled 8-colorings with no clashing color pairs).

48, 8256, 2779136, 981532672, 352524959744, 127365174788096, 46111939268444160, 16706602064729341952, 6054323596680792899584, 2194196637563524913037312, 795235812066308877870694400

Offset: 1

Author

R. H. Hardin, Dec 05 2013

Keywords

• nonn

Comments

Column 5 of A233202

Examples

			Some solutions for n=2
..0..1..2..3..0....0..1..2..1..3....0..1..2..3..5....0..1..2..0..3
..5..3..0..5..4....4..0..3..0..1....3..7..1..0..1....4..0..3..6..2
		

Links

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

Formula

Empirical: a(n) = 736*a(n-1) -203776*a(n-2) [phone]*a(n-3) -3665821696*a(n-4) [phone]*a(n-5) -10685878632448*a(n-6) -116548232544256*a(n-7) +35184372088832000*a(n-8) -1423137482249076736*a(n-9) +18446744073709551616*a(n-10) for n>11