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A206122
Number of (n+1)X3 0..2 arrays with every 2X2 subblock having nonzero determinant and having the same number of clockwise edge increases as its horizontal and vertical neighbors
1
170, 798, 3692, 18572, 93582, 491162, 2591052, 13911368, 74969572, 406919686, 2213161518, 12071381806, 65906319904, 360238467670, 1969917835712, 10777127170178, 58971800185530, 322748974999228, 1766538020755034
OFFSET
1,1
COMMENTS
Column 2 of A206128
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) +24*a(n-2) -109*a(n-3) -170*a(n-4) +664*a(n-5) +290*a(n-6) -954*a(n-7) -69*a(n-8) +1074*a(n-9) -119*a(n-10) -639*a(n-11) +479*a(n-12) +61*a(n-13) -299*a(n-14) +97*a(n-15) +36*a(n-16) -24*a(n-17) +4*a(n-18) for n>19
EXAMPLE
Some solutions for n=4
..2..1..0....1..2..0....2..2..1....0..2..0....0..1..2....2..0..1....2..1..1
..2..2..2....1..0..1....2..1..1....1..2..2....1..0..1....2..1..2....2..2..1
..2..1..2....0..1..2....1..1..2....1..1..2....2..1..0....0..2..1....1..2..2
..0..1..1....2..2..0....1..2..2....0..1..1....1..0..2....1..0..2....2..2..1
..1..1..0....1..0..1....1..1..2....1..1..0....2..1..0....2..1..0....2..0..1
CROSSREFS
Sequence in context: A173275 A301867 A281397 * A259293 A262426 A250965
KEYWORD
nonn
AUTHOR
R. H. Hardin Feb 04 2012
STATUS
approved