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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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 26 2013
STATUS
approved

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Last modified July 13 08:08 EDT 2024. Contains 374274 sequences. (Running on oeis4.)