A183340 Number of nX8 binary arrays with each 1 adjacent to exactly one 1 vertically and one 1 horizontally.

1, 19, 63, 193, 1005, 4133, 16029, 68662, 286079, 1170324, 4869491, 20218182, 83588667, 346493199, 1436419555, 5949727953, 24653341080, 102162618558, 423291469427, 1753914307948, 7267558737304, 30113168208503, 124774750283399

Offset: 1

Author

R. H. Hardin Jan 04 2011

Keywords

• nonn

Comments

Equivalent to all 1s connected only in 2X2 blocks

Column 8 of A183342

Examples

			Some solutions for 5X8
..0..1..1..0..0..1..1..0....1..1..0..0..0..0..0..0....1..1..0..0..0..0..0..0
..0..1..1..0..0..1..1..0....1..1..0..1..1..0..0..0....1..1..0..0..0..0..0..0
..0..0..0..0..0..0..0..0....0..0..0..1..1..0..0..0....0..0..0..0..0..0..0..0
..0..1..1..0..0..0..1..1....1..1..0..0..0..1..1..0....1..1..0..0..1..1..0..0
..0..1..1..0..0..0..1..1....1..1..0..0..0..1..1..0....1..1..0..0..1..1..0..0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=a(n-1)+4*a(n-2)+33*a(n-3)+40*a(n-4)-27*a(n-5)-190*a(n-6)-384*a(n-7)+149*a(n-8)+768*a(n-9)+398*a(n-10)-281*a(n-11)+312*a(n-12)-879*a(n-13)-1871*a(n-14)+351*a(n-15)+2551*a(n-16)-928*a(n-17)+499*a(n-18)+267*a(n-19)-947*a(n-20)-295*a(n-21)-55*a(n-22)+284*a(n-23)+192*a(n-24)+136*a(n-25)+98*a(n-26)-86*a(n-27)+17*a(n-28)-4*a(n-29)-19*a(n-30)+3*a(n-31)-12*a(n-32)