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A224601
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Number of (n+2)X5 0..2 matrices with each 3X3 subblock idempotent
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1
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297, 371, 482, 571, 782, 1086, 1455, 2010, 2843, 4018, 5720, 8226, 11877, 17199, 24995, 36409, 53111, 77574, 113415, 165921, 242852, 355585, 520784, 762873, 1117653, 1637589, 2399570, 3516286, 5152892, 7551432, 11066640, 16218405
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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) -6*a(n-2) +5*a(n-3) -4*a(n-4) +3*a(n-5) -a(n-6) for n>8.
Empirical g.f.: 297*x +371*x^2 -x^3*(-482+1357*x-1390*x^2+1026*x^3-876*x^4+366*x^5) / ( (x^3+x-1)*(x-1)^3 ). - R. J. Mathar, Aug 22 2016
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EXAMPLE
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Some solutions for n=3
..0..1..0..0..0....1..0..0..0..0....1..0..0..0..0....1..0..0..0..0
..0..1..0..0..0....1..0..0..0..0....1..0..0..0..0....1..0..0..0..0
..0..1..0..0..0....1..0..0..0..0....1..0..0..0..0....1..0..0..0..0
..0..1..0..0..0....0..0..0..0..0....0..0..0..0..1....0..0..0..0..0
..0..0..0..0..1....2..0..0..1..1....0..0..0..0..1....0..2..1..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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