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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

%I

%S 72,212,576,1696,4656,13736,38064,112504,314448,930968,2622192,

%T 7775032,22048848,65462648,186741360,555058840,1591397328,4734719768,

%U 13632852720,40593168760,117299196240,349504739000,1012931275632,3019805931352

%N 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).

%H R. H. Hardin, <a href="/A235179/b235179.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 16*a(n-2) - 65*a(n-4) + 14*a(n-6).

%F 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

%e Some solutions for n=4:

%e ..2..3....2..4....0..4....2..1....1..3....3..0....3..1....5..2....2..4....3..1

%e ..5..1....5..2....2..1....1..5....3..0....2..4....0..3....2..4....3..0....2..5

%e ..3..4....1..3....1..5....2..1....0..2....4..1....3..1....5..2....2..4....3..1

%e ..5..1....5..2....4..3....1..5....4..1....1..3....0..3....1..3....4..1....1..4

%e ..1..2....2..4....1..5....3..2....3..5....4..1....2..0....3..0....3..5....2..0

%Y Column 1 of A235186.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 04 2014

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Last modified January 22 15:13 EST 2022. Contains 350481 sequences. (Running on oeis4.)