A223684 Number of 6Xn 0..1 arrays with rows and antidiagonals unimodal.

64, 4096, 83737, 744272, 4106403, 17068664, 58944337, 178002044, 484800960, 1215412314, 2845433373, 6286999243, 13216899344, 26605753969, 51547601046, 96528061541, 175319673499, 309757515173, 533729732564, 898819275234

Offset: 1

Author

R. H. Hardin Mar 25 2013

Keywords

• nonn

Comments

Row 6 of A223680

Examples

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

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 + (44081/1360800)*n^10 + (67031/362880)*n^9 + (1007557/226800)*n^8 + (1582/675)*n^7 + (211210703/1360800)*n^6 - (60265871/120960)*n^5 + (11265884461/5443200)*n^4 - (118533836/14175)*n^3 + (2826245099/151200)*n^2 - (113088191/3960)*n + 23503 for n>3