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A234484 Number of (n+1) X (2+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 2 (constant-stress 1 X 1 tilings). 1
242, 926, 3540, 13554, 51950, 199340, 765738, 2944686, 11336132, 43687010, 168537102, 650861628, 2516088026, 9736457486, 37714463508, 146231331858, 567534230318, 2204734291532, 8572871807370, 33365331185646, 129974035943396 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 10*a(n-1) - 28*a(n-2) + a(n-3) + 54*a(n-4) + 24*a(n-5).
Empirical g.f.: 2*x*(121 - 747*x + 528*x^2 + 1920*x^3 + 768*x^4) / ((1 - 4*x)*(1 - 3*x - 2*x^2)*(1 - 3*x - 3*x^2)). - Colin Barker, Oct 15 2018
EXAMPLE
Some solutions for n=5:
2 3 2 1 3 0 3 0 0 1 1 3 2 3 1 2 0 2 1 1 1
2 1 2 1 1 0 3 2 0 2 0 0 2 1 1 1 1 1 3 1 3
1 2 1 2 0 1 3 0 0 2 2 0 0 1 3 0 2 0 1 1 1
2 1 2 2 2 1 3 2 0 1 3 3 3 2 2 2 2 2 1 3 1
2 3 2 3 1 2 1 2 2 2 2 0 3 0 2 2 0 2 2 2 2
2 1 2 1 1 0 1 0 2 1 3 3 1 0 0 2 2 2 3 1 3
CROSSREFS
Column 2 of A234490.
Sequence in context: A070284 A258894 A258887 * A160551 A258886 A354563
KEYWORD
nonn
AUTHOR
R. H. Hardin, Dec 26 2013
STATUS
approved

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Last modified April 25 06:49 EDT 2024. Contains 371964 sequences. (Running on oeis4.)