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A246248
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Number of permutations of [n] with exactly three occurrences of the consecutive step pattern up, down, down.
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2
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11259, 443718, 12450834, 297195804, 6589314360, 141014406600, 2982538767870, 63210091744620, 1354523537530620, 29518995185712180, 656767731733672680, 14956075051814966040, 349170616179434073825, 8366057002343951876610, 205839505389444095064510
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OFFSET
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10,1
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LINKS
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FORMULA
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a(n) ~ c * (3*sqrt(3)/(2*Pi))^n * n! * n^3, where c = 0.01095971939528021798... = c0 * (c0-1)^3 / (3^3 * 3!), and c0 = (1 + exp(Pi/sqrt(3))) * sqrt(3) / (2*Pi). - Vaclav Kotesovec, Aug 26 2014
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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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