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A234984 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, with no adjacent elements equal (constant stress tilted 1 X 1 tilings). 1
90, 370, 1640, 7554, 35072, 163416, 762002, 3554334, 16580250, 77345792, 360815494, 1683196556, 7852080772, 36629820538, 170877487282, 797140579074, 3718647299872, 17347426713674, 80925452066672, 377515864606272 (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) + 6*a(n-2) - 33*a(n-3) - 24*a(n-4) + 56*a(n-5) + 34*a(n-6) - 20*a(n-7) - 4*a(n-8).

Empirical g.f.: 2*x*(45 - 40*x - 375*x^2 + 52*x^3 + 916*x^4 + 346*x^5 - 324*x^6 - 60*x^7) / ((1 - 2*x^2)*(1 - 5*x - 4*x^2 + 23*x^3 + 16*x^4 - 10*x^5 - 2*x^6)). - Colin Barker, Oct 16 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 1 of A234991.

Sequence in context: A157888 A201103 A234991 * A158490 A304618 A187300

Adjacent sequences:  A234981 A234982 A234983 * A234985 A234986 A234987

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 02 2014

STATUS

approved

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Last modified October 19 12:10 EDT 2021. Contains 348088 sequences. (Running on oeis4.)