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A235191 Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5, with no adjacent elements equal (constant stress tilted 1 X 1 tilings). 1
136, 512, 1880, 7072, 26040, 98080, 361688, 1364512, 5038200, 19038496, 70378904, 266376736, 985819704, 3737000224, 13845090392, 52561201696, 194934374904, 741091305760, 2751206637848, 10473426441760, 38917567088568 (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) = 30*a(n-2) - 257*a(n-4) + 468*a(n-6).

Empirical g.f.: 8*x*(17 + 64*x - 275*x^2 - 1036*x^3 + 574*x^4 + 2188*x^5) / ((1 - 13*x^2)*(1 - 17*x^2 + 36*x^4)). - Colin Barker, Oct 17 2018

EXAMPLE

Some solutions for n=4:

..6..3....6..3....0..4....3..4....5..3....3..1....3..4....3..5....5..1....4..6

..2..4....3..5....2..1....0..6....2..5....1..4....6..2....6..3....1..2....6..3

..3..0....5..2....0..4....1..2....4..2....2..0....2..3....0..2....5..1....0..2

..1..3....2..4....3..2....5..1....0..3....0..3....6..2....6..3....2..3....6..3

..5..2....3..0....6..0....4..5....3..1....2..0....5..6....0..2....4..0....0..2

CROSSREFS

Column 1 of A235198.

Sequence in context: A116223 A124241 A235198 * A076331 A183901 A270341

Adjacent sequences:  A235188 A235189 A235190 * A235192 A235193 A235194

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 04 2014

STATUS

approved

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Last modified September 18 15:48 EDT 2020. Contains 337169 sequences. (Running on oeis4.)