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A234651 Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings). 1
160, 728, 3264, 15008, 67840, 315008, 1434624, 6722048, 30822400, 145614848, 671760384, 3197247488, 14829813760, 71052197888, 331140562944, 1595912880128, 7469054033920, 36183831216128, 169965785186304, 827149902675968 (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) = 4*a(n-1) + 44*a(n-2) - 176*a(n-3) - 480*a(n-4) + 1920*a(n-5).

Empirical g.f.: 8*x*(20 + 11*x - 836*x^2 - 240*x^3 + 8640*x^4) / ((1 - 4*x)*(1 - 20*x^2)*(1 - 24*x^2)). - Colin Barker, Oct 15 2018

EXAMPLE

Some solutions for n=5:

5 2 4 4 2 4 5 1 0 1 1 2 2 3 5 4 2 2 1 4

4 5 4 0 3 1 1 1 5 2 4 1 4 1 0 3 1 5 2 1

5 2 5 5 2 4 4 0 1 2 1 2 2 3 1 0 2 2 1 4

0 1 0 4 4 2 1 1 5 2 3 0 4 1 2 5 0 4 5 4

5 2 1 1 0 2 4 0 0 1 3 4 1 2 5 4 5 5 0 3

1 2 1 5 2 0 4 4 0 5 0 5 3 0 5 0 0 4 4 3

CROSSREFS

Column 1 of A234658.

Sequence in context: A233917 A233910 A234658 * A234898 A234891 A305272

Adjacent sequences: A234648 A234649 A234650 * A234652 A234653 A234654

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 29 2013

STATUS

approved

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Last modified January 29 14:44 EST 2023. Contains 359923 sequences. (Running on oeis4.)