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

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

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

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

Adjacent sequences: A206119 A206120 A206121 * A206123 A206124 A206125

Keyword

nonn

Author

R. H. Hardin Feb 04 2012

Status

approved