A223572 Number of nX4 0..2 arrays with antidiagonals unimodal.

81, 6561, 352836, 16230456, 746600976, 34343644896, 1579807665216, 72671152599936, 3342873019597056, 153772158901464576, 7073519309467370496, 325381888235499042816, 14967566858832955969536, 688508075506315974598656

Offset: 1

Author

R. H. Hardin Mar 22 2013

Keywords

• nonn

Comments

Column 4 of A223576

Examples

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

Links

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

Formula

Let U(z) = (z^4+6*z^3+23*z^2+18*z+24)/24

a(n) = U(min(n,4))^(max(n,4)-min(n,4)+1) * product{ U(i)^2 , i=1..(min(n,4)-1) }

a(n) = 46*a(n-1) for n>3