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A234262 Number of (n+1) X (4+1) 0..2 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
244, 358, 560, 988, 1816, 3616, 7304, 15544, 33064, 73288, 161000, 367528, 826216, 1930216, 4416104, 10507624, 24366184, 58801768, 137742440, 335934568, 792768616, 1948301416, 4622131304, 11420979304, 27195392104, 67451347048 (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) = 3*a(n-1) + 6*a(n-2) - 24*a(n-3) + 4*a(n-4) + 36*a(n-5) - 24*a(n-6).

Empirical g.f.: 2*x*(122 - 187*x - 989*x^2 + 1508*x^3 + 1554*x^4 - 2268*x^5) / ((1 - x)*(1 - 2*x)*(1 - 2*x^2)*(1 - 6*x^2)). - Colin Barker, Oct 14 2018

EXAMPLE

Some solutions for n=5:

  2 2 0 0 0      0 0 0 0 0      0 2 0 2 0      2 2 1 0 0

  2 0 0 2 0      2 0 2 0 2      0 0 0 0 0      2 0 1 2 0

  2 2 0 0 0      0 0 0 0 0      0 2 0 2 0      2 2 1 0 0

  2 0 0 2 0      2 0 2 0 2      1 1 1 1 1      2 0 1 2 0

  2 2 0 0 0      2 2 2 2 2      2 0 2 0 2      2 2 1 0 0

  2 0 0 2 0      2 0 2 0 2      2 2 2 2 2      2 0 1 2 0

CROSSREFS

Column 4 of A234266.

Sequence in context: A051002 A044987 A201998 * A031786 A328206 A135409

Adjacent sequences:  A234259 A234260 A234261 * A234263 A234264 A234265

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 22 2013

STATUS

approved

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Last modified August 10 20:05 EDT 2022. Contains 356039 sequences. (Running on oeis4.)