A224413 Number of 6Xn 0..1 arrays with rows unimodal and antidiagonals nondecreasing.

64, 972, 4636, 13440, 31710, 68282, 139638, 275766, 530583, 999049, 1844709, 3342831, 5946316, 10384152, 17805490, 29986574, 49622914, 80735424, 129226948, 203634878, 316136662, 483878162, 730710330, 1089437826, 1604704333

Offset: 1

Author

R. H. Hardin Apr 05 2013

Keywords

• nonn

Comments

Row 6 of A224409

Examples

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

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 + (199/43545600)*n^10 + (1/10752)*n^9 + (19951/14515200)*n^8 + (5143/345600)*n^7 + (6148357/43545600)*n^6 + (3015961/1451520)*n^5 + (128983289/10886400)*n^4 + (40193333/604800)*n^3 + (444089893/1663200)*n^2 - (4351/20)*n - 222 for n>4