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A116738
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Number of permutations of length n which avoid the patterns 3214, 4123, 4132.
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0
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1, 2, 6, 21, 74, 260, 913, 3206, 11258, 39533, 138822, 487480, 1711809, 6011098, 21108254, 74122629, 260285106, 914003420, 3209566097, 11270542654, 39577041842, 138976648157, 488023051598, 1713715951920, 6017794352641
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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(2x-1)}/{x^3-2x^2+4x-1}
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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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