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

1,2

Comments

Column 1 of A186218

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

Example

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

Crossrefs

Sequence in context: A369954 A109836 A332047 * A205748 A352109 A349674

Adjacent sequences: A186208 A186209 A186210 * A186212 A186213 A186214

Keyword

nonn

Author

R. H. Hardin Feb 15 2011

Status

approved