A224154 Number of nX4 0..1 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.

11, 56, 187, 574, 1783, 5657, 18408, 61140, 205390, 694018, 2350061, 7961090, 26964678, 91303265, 309082754, 1046163241, 3540718751, 11983122960, 40555030532, 137252283821, 464510611475, 1572073476421, 5320479934245

Offset: 1

Author

R. H. Hardin Mar 31 2013

Keywords

• nonn

Comments

Column 4 of A224158

Examples

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

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -5*a(n-2) -2*a(n-3) -3*a(n-4) +18*a(n-5) -18*a(n-6) +27*a(n-7) -3*a(n-8) -4*a(n-9) -8*a(n-11) -6*a(n-12) -6*a(n-13) for n>14