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A235179 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 5, with no adjacent elements equal (constant stress tilted 1 X 1 tilings). 1
72, 212, 576, 1696, 4656, 13736, 38064, 112504, 314448, 930968, 2622192, 7775032, 22048848, 65462648, 186741360, 555058840, 1591397328, 4734719768, 13632852720, 40593168760, 117299196240, 349504739000, 1012931275632, 3019805931352 (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) = 16*a(n-2) - 65*a(n-4) + 14*a(n-6).

Empirical g.f.: 4*x*(18 + 53*x - 144*x^2 - 424*x^3 + 30*x^4 + 95*x^5) / ((1 - 7*x^2)*(1 - 9*x^2 + 2*x^4)). - Colin Barker, Oct 17 2018

EXAMPLE

Some solutions for n=4:

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

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

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

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

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

CROSSREFS

Column 1 of A235186.

Sequence in context: A250786 A302886 A235186 * A204492 A204485 A344179

Adjacent sequences:  A235176 A235177 A235178 * A235180 A235181 A235182

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 04 2014

STATUS

approved

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Last modified November 30 17:12 EST 2021. Contains 349424 sequences. (Running on oeis4.)