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A224600
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Number of (n+2)X4 0..2 matrices with each 3X3 subblock idempotent
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1
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178, 272, 371, 449, 630, 894, 1221, 1707, 2440, 3476, 4979, 7189, 10414, 15114, 22001, 32083, 46840, 68452, 100119, 146509, 214482, 314086, 460049, 673947, 987416, 1446808, 2120063, 3106745, 4552782, 6672030, 9777921, 14329803, 21000892
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OFFSET
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1,1
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COMMENTS
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Column 2 of A224606
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..210
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FORMULA
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Empirical: a(n) = 3*a(n-1) -2*a(n-2) -a(n-3) +a(n-4) -a(n-5) +2*a(n-6) -a(n-7) for n>9.
Empirical g.f.: 178*x + 272*x^2 -x^3*(-371 +664*x -25*x^2 -273*x^3 +123*x^4 -384*x^5 +268*x^6) / ( (1+x)*(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
..1..0..0..0....1..0..0..0....1..0..0..2....1..1..1..1....1..1..2..1
..1..0..0..0....1..0..0..0....1..0..0..2....0..0..0..0....0..0..0..0
..1..0..0..0....1..0..0..0....1..0..0..1....0..0..0..0....0..0..0..0
..0..0..0..1....0..0..0..0....2..0..0..1....1..1..1..1....0..0..0..0
..1..0..0..1....2..0..0..0....1..0..0..1....0..0..0..0....2..1..1..1
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CROSSREFS
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Sequence in context: A046436 A114081 A217037 * A279093 A297400 A297600
Adjacent sequences: A224597 A224598 A224599 * A224601 A224602 A224603
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin Apr 11 2013
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STATUS
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approved
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