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A234992 Number of (n+1)X(1+1) 0..6 arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 2, with no adjacent elements equal (constant stress tilted 1X1 tilings) 1

%I

%S 172,916,5280,31944,196148,1214044,7532324,46791008,290776568,

%T 1807339968,11234293404,69833627132,434097609572,2698436446136,

%U 16774037447840,104270950787408,648170340713028,4029164730233420,25046145986188500

%N Number of (n+1)X(1+1) 0..6 arrays with every 2X2 subblock having its diagonal sum differing from its antidiagonal sum by 2, with no adjacent elements equal (constant stress tilted 1X1 tilings)

%C Column 1 of A234998

%H R. H. Hardin, <a href="/A234992/b234992.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) +21*a(n-2) -70*a(n-3) -144*a(n-4) +326*a(n-5) +381*a(n-6) -549*a(n-7) -351*a(n-8) +198*a(n-9) +54*a(n-10)

%e Some solutions for n=5

%e ..4..1....3..4....1..0....1..0....4..1....3..4....4..3....3..4....1..4....0..3

%e ..6..5....2..1....0..1....5..2....1..0....1..0....0..1....2..5....0..1....3..4

%e ..5..2....5..2....1..4....4..3....5..6....5..2....1..0....3..4....3..6....2..5

%e ..6..1....4..3....2..3....5..6....3..2....6..5....0..1....2..5....2..3....5..6

%e ..5..2....5..2....6..5....1..0....4..5....5..2....3..2....5..6....6..5....6..5

%e ..6..5....1..0....0..1....4..5....1..4....6..5....4..1....0..3....0..1....5..6

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 02 2014

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Last modified May 28 08:23 EDT 2022. Contains 354112 sequences. (Running on oeis4.)