A210383 - OEIS

A210383

Number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having one, two or three distinct clockwise edge differences.

73, 597, 4881, 39909, 326313, 2668077, 21815361, 178371909, 1458446553, 11924895357, 97503147441, 797228275509, 6518486222793, 53297987467437, 435787600217121, 3563189559812709, 29134192512207033, 238213869649684317

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OFFSET

1,1

COMMENTS

Column 1 of A210390.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) - 6*a(n-2) - 6*a(n-3).

Empirical g.f.: x*(73 - 60*x - 54*x^2) / (1 - 9*x + 6*x^2 + 6*x^3). - Colin Barker, Jul 15 2018

EXAMPLE

Some solutions for n=4:

..0..0....2..1....2..1....0..2....2..1....2..0....2..1....1..2....1..2....0..2

..2..1....0..0....1..1....2..0....0..0....1..0....0..0....0..1....0..2....0..1

..2..0....2..0....0..1....0..2....1..1....0..0....1..1....2..1....0..2....2..1

..1..0....0..2....2..2....0..1....1..2....1..0....1..0....2..0....2..2....1..0

..0..0....1..1....1..2....1..2....1..1....2..1....2..1....0..2....0..2....0..0

CROSSREFS

Cf. A210390.

Sequence in context: A235465 A201263 A210390 * A142675 A167187 A177095

Adjacent sequences: A210380 A210381 A210382 * A210384 A210385 A210386

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 20 2012

STATUS

approved