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A230265
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Denominators of eta(2*n)/Pi^(2*n), where eta(n) is the Dirichlet eta function.
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2
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2, 12, 720, 30240, 1209600, 6842880, 1307674368000, 74724249600, 1524374691840000, 5109094217170944000, 802857662698291200000, 287777551824322560000, 1693824136731743669452800000, 186134520519971831808000000
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OFFSET
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0,1
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COMMENTS
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The first 5 terms of this sequence are the same as in A060055.
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LINKS
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FORMULA
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a(n) = A036280(n)*Pi^(2*n)/(zeta(2*n)*(1 - 2^(1-2*n))).
a(n) = denominator((-1)^(n+1)*BernoulliB(2*n)*(2^(2*n-1) - 1)/(2*n)!).
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PROG
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(PARI) for(n=0, 7, print1(2*denominator(polcoeff(Ser(1/sin(x)), 2*n-1)), ", "));
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CROSSREFS
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KEYWORD
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nonn,easy,frac
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AUTHOR
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STATUS
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approved
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