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A200250
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Number of 0..7 arrays x(0..n-1) of n elements with each no smaller than the sum of its previous elements modulo 8.
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1
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8, 36, 164, 750, 3434, 15724, 71970, 329455, 1508139, 6903702, 31602661, 144665637, 662227235, 3031438038, 13876832881, 63523149100, 290786125630, 1331114279973, 6093362338144, 27893220846536, 127685131134366, 584496598744029
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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) = a(n-1) +9*a(n-2) +24*a(n-3) +36*a(n-4) +35*a(n-5) +21*a(n-6) +7*a(n-7) +a(n-8).
Empirical g.f.: x*(2 + x)*(2 + 2*x + x^2)*(2 + 4*x + 6*x^2 + 4*x^3 + x^4) / (1 - x - 9*x^2 - 24*x^3 - 36*x^4 - 35*x^5 - 21*x^6 - 7*x^7 - x^8). - Colin Barker, May 20 2018
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EXAMPLE
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Some solutions for n=6:
..3....1....6....3....2....3....2....1....0....6....3....3....0....7....2....1
..6....3....7....7....6....5....6....4....3....6....7....5....2....7....6....4
..7....6....7....7....4....2....3....5....6....7....6....1....7....7....3....5
..5....2....4....1....5....2....6....7....3....6....6....1....5....6....6....6
..5....5....1....3....6....5....1....3....7....2....6....3....6....7....5....2
..7....5....5....6....7....3....5....4....5....7....5....6....7....7....7....7
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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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