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A131846
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Expansion of series reversion of x*(1-6*x)/(1-x).
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4
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1, 5, 55, 755, 11605, 191105, 3296755, 58810055, 1075986505, 20079780605, 380733295855, 7314056109755, 142049912523805, 2784519380488505, 55019843803653355, 1094695713838691855, 21912997682690751505, 440999873506064578805, 8917597017732200569255
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OFFSET
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1,2
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COMMENTS
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The Hankel transform of this sequence is 30^C(n+1,2).
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LINKS
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FORMULA
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a(n) = Sum_{k=0..n} A086810(n,k)*5^k .
Recurrence: n*a(n) = 11*(2*n-3)*a(n-1) - (n-3)*a(n-2). - Vaclav Kotesovec, Aug 20 2013
a(n) ~ sqrt(11*sqrt(30)-60) * (11+2*sqrt(30))^n/(12*sqrt(Pi)*n^(3/2)). - Vaclav Kotesovec, Aug 20 2013
G.f.: (1 + x - sqrt(1 - 22*x + x^2))/12.
G.f.: x/(1 - 5*x/(1 - 6*x/(1 - 5*x/(1 - 6*x/(1 - 5*x/(1 - ...)))))), a continued fraction. (End)
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MATHEMATICA
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Rest[CoefficientList[InverseSeries[Series[x*(1-6*x)/(1-x), {x, 0, 20}], x], x]] (* Vaclav Kotesovec, Aug 20 2013 *)
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PROG
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(PARI) Vec(serreverse(x*(1-6*x)/(1-x)+O(x^66))) /* Joerg Arndt, Feb 06 2013 */
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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