A223618 Number of nX6 0..1 arrays with rows and columns unimodal.

22, 484, 6504, 57238, 367216, 1856100, 7795951, 28248007, 90732638, 263650284, 703980614, 1748547620, 4079672416, 9012596316, 18975151965, 38281575869, 74344179766, 139521245076, 253869738212, 449160402594, 774624001120

Offset: 1

Author

R. H. Hardin Mar 24 2013

Keywords

• nonn

Comments

Column 6 of A223620

Examples

			Some solutions for n=4
..1..1..0..0..0..0....0..0..1..0..0..0....0..0..1..1..1..1....1..1..1..1..1..1
..0..1..0..0..0..0....0..0..0..1..0..0....0..0..1..1..1..1....1..1..1..1..1..1
..0..0..1..0..0..0....0..0..0..1..1..0....0..0..0..1..1..1....0..0..0..1..1..1
..0..0..1..1..0..0....1..1..0..0..0..0....0..0..0..0..1..1....0..0..0..1..1..1
		

Links

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

Formula

Empirical: a(n) = (271/5443200)*n^12 + (2327/3326400)*n^11 + (39107/5443200)*n^10 + (1579/36288)*n^9 + (52553/259200)*n^8 + (192371/302400)*n^7 + (8636441/5443200)*n^6 + (56113/20160)*n^5 + (2901677/680400)*n^4 + (523927/113400)*n^3 + (23969/5400)*n^2 + (33487/13860)*n + 1