A186211 Number of (n+1)X2 0..2 arrays with every 2X2 subblock determinant equal to some horizontal or vertical neighbor 2X2 subblock determinant.

0, 175, 609, 3593, 15055, 76263, 353985, 1729733, 8225815, 39664199, 189800057, 911926009, 4372168391, 20986330867, 100672272185, 483086490365, 2317736112319, 11120991460315, 53358239027713, 256018285828501

Offset: 1

Author

R. H. Hardin Feb 15 2011

Keywords

• nonn

Comments

Column 1 of A186218

Examples

			Some solutions for 3X2
..1..0....1..0....0..2....0..2....1..1....2..0....2..1....0..0....0..2....0..0
..1..0....1..1....0..0....0..0....1..1....2..0....1..1....1..0....0..1....0..0
..0..0....1..2....0..0....1..1....1..1....1..0....1..2....2..0....0..1....0..2
		

Links

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

Formula

Empirical: a(n)=6*a(n-1)+a(n-2)-48*a(n-3)+77*a(n-4)+28*a(n-5)-238*a(n-6)+230*a(n-7)-67*a(n-8)+170*a(n-9)+100*a(n-10)-432*a(n-11)+256*a(n-12)-532*a(n-13)+296*a(n-14)+144*a(n-15)-320*a(n-16)+512*a(n-17) for n>18