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A258540
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Number of (n+2)X(3+2) 0..1 arrays with no 3x3 subblock diagonal sum less than the antidiagonal sum or central row sum equal to the central column sum
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1
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2520, 8836, 20736, 57600, 142544, 381924, 956736, 2496400, 6344576, 16467364, 42350672, 110082064, 285367424, 743652900, 1936887872, 5057485456, 13206499776, 34526842596, 90279314432, 236188224064, 617983034784
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 4*a(n-1) +9*a(n-2) -51*a(n-3) -20*a(n-4) +275*a(n-5) -65*a(n-6) -820*a(n-7) +465*a(n-8) +1485*a(n-9) -1180*a(n-10) -1685*a(n-11) +1685*a(n-12) +1180*a(n-13) -1485*a(n-14) -465*a(n-15) +820*a(n-16) +65*a(n-17) -275*a(n-18) +20*a(n-19) +51*a(n-20) -9*a(n-21) -4*a(n-22) +a(n-23) for n>26
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EXAMPLE
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Some solutions for n=4
..1..1..1..0..0....0..0..0..0..0....1..0..1..0..0....0..1..1..0..1
..1..1..0..1..0....1..1..1..1..1....1..0..1..0..1....1..1..0..0..0
..0..1..0..1..0....0..0..0..0..0....1..1..1..1..1....0..1..1..1..1
..1..0..1..0..1....1..1..1..1..1....0..1..0..1..0....1..1..0..0..1
..0..0..1..0..1....0..0..0..0..0....0..0..0..0..1....0..1..1..1..1
..0..0..0..0..0....0..0..0..0..0....0..1..1..1..1....1..1..0..1..1
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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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