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A280809
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Number of nX7 0..1 arrays with no element equal to more than two of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
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1
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0, 1047, 24490, 133067, 521862, 1736603, 5219491, 14672850, 39446188, 102668319, 261032587, 651872767, 1605291205, 3909190755, 9432062891, 22579858190, 53688882185, 126896063565, 298328702932, 698005209403, 1626059718118
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OFFSET
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1,2
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COMMENTS
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Column 7 of A280810.
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..151
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FORMULA
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Empirical: a(n) = 13*a(n-1) -72*a(n-2) +220*a(n-3) -400*a(n-4) +432*a(n-5) -256*a(n-6) +64*a(n-7) +6*a(n-8) -54*a(n-9) +183*a(n-10) -249*a(n-11) -51*a(n-12) +573*a(n-13) -672*a(n-14) +264*a(n-15) +33*a(n-16) +39*a(n-17) -156*a(n-18) +12*a(n-19) +225*a(n-20) -57*a(n-21) -390*a(n-22) +402*a(n-23) -19*a(n-24) -173*a(n-25) +66*a(n-26) +126*a(n-27) -156*a(n-28) +33*a(n-30) +93*a(n-31) -96*a(n-32) +2*a(n-33) +43*a(n-34) -45*a(n-35) -20*a(n-36) +74*a(n-37) -30*a(n-38) -18*a(n-39) +15*a(n-40) -3*a(n-41) -9*a(n-42) +15*a(n-43) -3*a(n-44) -3*a(n-45) -a(n-48) +a(n-49) for n>60
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EXAMPLE
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Some solutions for n=4
..0..1..0..0..1..0..1. .0..1..0..0..1..1..0. .0..0..1..0..0..1..0
..1..1..1..0..1..0..1. .0..1..0..1..0..1..1. .1..1..0..1..0..1..0
..0..0..1..0..1..0..1. .1..0..0..1..0..0..0. .0..1..0..1..0..1..0
..1..1..0..1..0..0..1. .1..1..1..0..1..1..0. .1..1..0..1..0..1..1
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CROSSREFS
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Cf. A280810.
Sequence in context: A226114 A249653 A056092 * A252307 A236273 A251375
Adjacent sequences: A280806 A280807 A280808 * A280810 A280811 A280812
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Jan 08 2017
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STATUS
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approved
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