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A234819
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Number of (n+1) X (4+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 6 (constant-stress 1 X 1 tilings).
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1
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9716, 22098, 47136, 129384, 325424, 994812, 2794776, 9151956, 27722816, 95289828, 304241976, 1084006404, 3595734464, 13167262212, 44957454456, 168155707716, 587295900416, 2233218785028, 7943114997816, 30594914582724, 110455840695104
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 8*a(n-1) +60*a(n-2) -620*a(n-3) -1210*a(n-4) +20740*a(n-5) +1580*a(n-6) -392180*a(n-7) +353267*a(n-8) +4606324*a(n-9) -7135240*a(n-10) -34677440*a(n-11) +72387960*a(n-12) +165390560*a(n-13) -443380480*a(n-14) -464032320*a(n-15) +1696321584*a(n-16) +566607168*a(n-17) -3948347520*a(n-18) +465384960*a(n-19) +5084985600*a(n-20) -2142028800*a(n-21) -2757888000*a(n-22) +1741824000*a(n-23).
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EXAMPLE
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Some solutions for n=4:
1 4 1 4 1 2 5 1 5 2 0 3 3 5 3 4 0 3 1 3
5 2 5 2 5 3 0 2 0 3 3 0 6 2 6 1 3 0 4 0
1 4 1 4 1 3 6 2 6 3 1 4 4 6 4 6 2 5 3 5
5 2 5 2 5 4 1 3 1 4 3 0 6 2 6 1 3 0 4 0
3 6 3 6 3 1 4 0 4 1 0 3 3 5 3 4 0 3 1 3
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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