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Denominator of x(n) = Sum_{k=1..n} ((odd part of k)/(k^4)).
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%I #9 Dec 25 2019 08:34:34

%S 1,16,432,6912,864000,864000,296352000,4741632000,128024064000,

%T 128024064000,170400029184000,170400029184000,374368864117248000,

%U 374368864117248000,14974754564689920,239596073035038720

%N Denominator of x(n) = Sum_{k=1..n} ((odd part of k)/(k^4)).

%C Numerator of x(n) = A111920(n);

%C x(n) = A111920(n)/a(n) -> 14*zeta(3)/15.

%D G. Pólya and G. Szegő, Problems and Theorems in Analysis II (Springer 1924, reprinted 1972), Part Eight, Chap. 1, Sect. 6, Problem 50.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/OddPart.html">Odd Part</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AperysConstant.html">Apery's constant</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/RiemannZetaFunction.html">Riemann Zeta Function</a>

%Y Cf. A000265, A002117, A111930, A111919, A111920, A111923.

%K nonn,frac

%O 1,2

%A _Reinhard Zumkeller_, Aug 21 2005