A225013 Number of 6Xn 0..1 arrays with rows unimodal and columns nondecreasing.

7, 49, 252, 1036, 3612, 11088, 30738, 78354, 186142, 416394, 884236, 1794196, 3497248, 6577474, 11980667, 21201211, 36548573, 61520899, 101320712, 163556776, 259187048, 403770544, 619111172, 935394436, 1393938716, 2050706932

Offset: 1

Author

R. H. Hardin Apr 23 2013

Keywords

• nonn

Comments

Row 6 of A225010

Examples

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

Links

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

Formula

Empirical: a(n) = (1/479001600)*n^12 + (1/7257600)*n^11 + (187/43545600)*n^10 + (13/161280)*n^9 + (14671/14515200)*n^8 + (3043/345600)*n^7 + (2380201/43545600)*n^6 + (347911/1451520)*n^5 + (8129699/10886400)*n^4 + (923183/604800)*n^3 + (913741/415800)*n^2 + (49/40)*n + 1