A223768 Number of nX6 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing.

22, 169, 607, 1601, 3699, 8007, 16742, 34096, 67890, 132115, 251110, 465910, 843960, 1493505, 2584666, 4379914, 7277630, 11873716, 19047873, 30083272, 46831011, 71934087, 109129744, 163654129, 242779358, 356520541, 518559236, 747440414

Offset: 1

Author

R. H. Hardin Mar 27 2013

Keywords

• nonn

Comments

Column 6 of A223770

Examples

			Some solutions for n=3
..0..1..0..0..0..0....1..0..0..0..0..0....0..1..0..0..0..0....0..1..1..1..1..0
..1..1..1..1..0..0....1..1..1..0..0..0....0..1..1..1..0..0....0..1..1..1..1..1
..0..1..1..1..1..1....0..1..1..1..1..0....1..1..1..1..1..1....0..0..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 - (1/15966720)*n^11 + (23/8709120)*n^10 - (59/1451520)*n^9 + (22591/14515200)*n^8 - (1159/53760)*n^7 + (713737/1741824)*n^6 - (1665749/290304)*n^5 + (795178259/10886400)*n^4 - (220668799/362880)*n^3 + (73774259/20790)*n^2 - (340682581/27720)*n + 20228 for n>8