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A235276 Number of (n+1) X (6+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 5 (constant stress 1 X 1 tilings). 1
2800, 3844, 5096, 7936, 11704, 20440, 33464, 64168, 115480, 238024, 463736, 1009096, 2091544, 4737160, 10277624, 23969608, 53719960, 127968904, 293325176, 709379656, 1651106584, 4035596680, 9490235384, 23366392648, 55327897240 (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) = a(n-1) + 15*a(n-2) - 15*a(n-3) - 80*a(n-4) + 80*a(n-5) + 180*a(n-6) - 180*a(n-7) - 144*a(n-8) + 144*a(n-9).

Empirical g.f.: 4*x*(700 + 261*x - 10187*x^2 - 3205*x^3 + 52247*x^4 + 12414*x^5 - 111834*x^6 - 15264*x^7 + 83808*x^8) / ((1 - x)*(1 - 2*x)*(1 + 2*x)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - 6*x^2)). - Colin Barker, Oct 18 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 6 of A235280.

Sequence in context: A236943 A236777 A210104 * A115471 A292011 A306849

Adjacent sequences:  A235273 A235274 A235275 * A235277 A235278 A235279

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 05 2014

STATUS

approved

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Last modified March 29 15:16 EDT 2020. Contains 333107 sequences. (Running on oeis4.)