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A235274 Number of (n+1) X (4+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
520, 844, 1280, 2344, 3952, 7936, 14672, 31504, 62800, 141424, 298640, 695344, 1530832, 3647536, 8265872, 20008624, 46236880, 113126704, 264832400, 652640944, 1540956112, 3815788336, 9060105872, 22507117744, 53636823760, 133528827184 (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*(130 + 81*x - 1841*x^2 - 949*x^3 + 9167*x^4 + 3486*x^5 - 19026*x^6 - 4032*x^7 + 13824*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..0..4..0....2..4..3..4..3....2..0..1..0..4....2..4..0..4..2

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

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

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

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

CROSSREFS

Column 4 of A235280.

Sequence in context: A051983 A250768 A043626 * A147854 A147856 A094903

Adjacent sequences:  A235271 A235272 A235273 * A235275 A235276 A235277

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 05 2014

STATUS

approved

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Last modified May 29 08:07 EDT 2020. Contains 334697 sequences. (Running on oeis4.)