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A234444 Number of (n+1) X (1+1) 0..4 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
160, 1120, 8064, 58720, 428800, 3137920, 22953984, 168075520, 1229731840, 9005086720, 65887739904, 482487224320, 3530236641280, 25851483627520, 189148815949824, 1385113412485120, 10134527552389120, 74213894381240320 (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) = 60*a(n-2) - 344*a(n-4).

Empirical g.f.: 32*x*(5 + 35*x - 48*x^2 - 265*x^3) / (1 - 60*x^2 + 344*x^4). - Colin Barker, Oct 15 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 1 of A234450.

Sequence in context: A234891 A305272 A234450 * A166778 A236518 A120103

Adjacent sequences:  A234441 A234442 A234443 * A234445 A234446 A234447

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 26 2013

STATUS

approved

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Last modified February 25 22:37 EST 2021. Contains 341618 sequences. (Running on oeis4.)