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A234491 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 2 (constant stress 1 X 1 tilings). 1
250, 1834, 13464, 99142, 728536, 5368636, 39476802, 291119578, 2142048610, 15807820384, 116387461374, 859523654392, 6332338846996, 46797181439986, 344979511889562, 2551214650069978, 18818390917298920, 139260488424222934 (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) = 5*a(n-1) + 74*a(n-2) - 295*a(n-3) - 1008*a(n-4) + 840*a(n-5).

Empirical g.f.: 2*x*(125 + 292*x - 7103*x^2 - 15072*x^3 + 14760*x^4) / ((1 - 56*x^2)*(1 - 5*x - 18*x^2 + 15*x^3)). - Colin Barker, Oct 15 2018

EXAMPLE

Some solutions for n=4:

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

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

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

..4..4....5..4....2..4....4..4....2..2....3..4....3..3....4..3....3..2....5..0

..5..3....1..2....5..5....3..1....1..3....2..1....1..3....3..4....4..1....4..1

CROSSREFS

Column 1 of A234497.

Sequence in context: A045185 A122270 A234497 * A249199 A249214 A249321

Adjacent sequences:  A234488 A234489 A234490 * A234492 A234493 A234494

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 26 2013

STATUS

approved

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Last modified October 21 19:29 EDT 2019. Contains 328315 sequences. (Running on oeis4.)