A228758 Number of 6Xn binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally.

32, 144, 3111, 29608, 418370, 4823826, 61534448, 746135864, 9275632316, 113914525214, 1407229306722, 17335288371612, 213833281859269, 2636011878793640, 32504748521697000, 400762354405626468

Offset: 1

Author

R. H. Hardin Sep 02 2013

Keywords

• nonn

Comments

Row 6 of A228754

Examples

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

Links

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

Formula

Empirical: a(n) = a(n-1) +119*a(n-2) +397*a(n-3) -1395*a(n-4) -5213*a(n-5) +8797*a(n-6) +24443*a(n-7) -36756*a(n-8) -45888*a(n-9) +84092*a(n-10) +19388*a(n-11) -83412*a(n-12) +24912*a(n-13) +22741*a(n-14) -12257*a(n-15) -1459*a(n-16) +1607*a(n-17) -49*a(n-18) -71*a(n-19) +3*a(n-20) +a(n-21)