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A234437 Number of (n+1) X (2+1) 0..2 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 1 (constant stress 1 X 1 tilings). 1
120, 582, 2804, 13676, 66228, 324556, 1578036, 7767916, 37908724, 187373548, 917502516, 4551845676, 22356377716, 111280430060, 548022172852, 2735782774700, 13504607285492, 67587887187308, 334314078617908 (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) = 5*a(n-1) + 24*a(n-2) - 130*a(n-3) + 36*a(n-4) + 80*a(n-5) - 32*a(n-6).

Empirical g.f.: 2*x*(60 - 9*x - 1493*x^2 + 644*x^3 + 946*x^4 - 420*x^5) / ((1 - 5*x + 2*x^2)*(1 - 26*x^2 + 16*x^4)). - Colin Barker, Oct 15 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Column 2 of A234443.

Sequence in context: A115619 A152622 A100145 * A090216 A265041 A280425

Adjacent sequences:  A234434 A234435 A234436 * A234438 A234439 A234440

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 26 2013

STATUS

approved

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Last modified September 25 06:32 EDT 2020. Contains 337335 sequences. (Running on oeis4.)