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A234483 Number of (n+1) X (1+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant stress 1 X 1 tilings). 1
62, 242, 944, 3686, 14402, 56312, 220334, 862706, 3380192, 13252982, 51996674, 204137576, 801957182, 3152502002, 12400248464, 48805735046, 192207885122, 757400598872, 2986264405454, 11780750826866, 46500068952512 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) - 9*a(n-2) - 12*a(n-3).

Empirical g.f.: 2*x*(31 - 96*x - 96*x^2) / ((1 - 4*x)*(1 - 3*x - 3*x^2)). - Colin Barker, Oct 15 2018

EXAMPLE

Some solutions for n=5:

..3..2....1..0....2..0....0..3....0..0....2..2....0..3....1..1....1..2....2..2

..3..0....0..1....0..0....0..1....3..1....2..0....1..2....3..1....1..0....3..1

..1..0....2..1....0..2....0..3....1..1....1..1....3..2....0..0....3..0....0..0

..0..1....1..2....3..3....2..3....0..2....0..2....3..0....1..3....1..0....0..2

..1..0....1..0....0..2....0..3....2..2....1..1....3..2....3..3....0..1....3..3

..2..3....1..2....1..1....2..3....1..3....0..2....2..3....3..1....3..2....3..1

CROSSREFS

Column 1 of A234490.

Sequence in context: A230007 A318561 A234490 * A158067 A045220 A100158

Adjacent sequences:  A234480 A234481 A234482 * A234484 A234485 A234486

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 26 2013

STATUS

approved

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Last modified August 18 04:50 EDT 2019. Contains 326072 sequences. (Running on oeis4.)