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A234484 Number of (n+1) X (2+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
242, 926, 3540, 13554, 51950, 199340, 765738, 2944686, 11336132, 43687010, 168537102, 650861628, 2516088026, 9736457486, 37714463508, 146231331858, 567534230318, 2204734291532, 8572871807370, 33365331185646, 129974035943396 (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) = 10*a(n-1) - 28*a(n-2) + a(n-3) + 54*a(n-4) + 24*a(n-5).

Empirical g.f.: 2*x*(121 - 747*x + 528*x^2 + 1920*x^3 + 768*x^4) / ((1 - 4*x)*(1 - 3*x - 2*x^2)*(1 - 3*x - 3*x^2)). - Colin Barker, Oct 15 2018

EXAMPLE

Some solutions for n=5:

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

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

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

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

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

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

CROSSREFS

Column 2 of A234490.

Sequence in context: A070284 A258894 A258887 * A160551 A258886 A165935

Adjacent sequences:  A234481 A234482 A234483 * A234485 A234486 A234487

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 26 2013

STATUS

approved

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Last modified August 24 18:12 EDT 2019. Contains 326295 sequences. (Running on oeis4.)