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A116806
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Number of permutations of length n which avoid the patterns 2314, 4213, 4312.
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0
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1, 2, 6, 21, 75, 262, 891, 2964, 9700, 31374, 100639, 320949, 1019396, 3228687, 10206180, 32219494, 101619194, 320303001, 1009163739, 3178610330, 10009874543, 31518335944, 99233864812, 312414443206, 983524845979
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OFFSET
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1,2
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LINKS
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FORMULA
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G.f.: A(x) = -{x(4x^5-13x^4+23x^3-19x^2+7x-1)}/{(2x-1)^2(x-1)(-1+4x-3x^2+x^3)}
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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