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 A234145 a(n) = denominator of sum_(k=1..n) 1/(2*k-1)^n. 2
 1, 1, 9, 3375, 121550625, 3101364196875, 1730690595263722640625, 376292999446907764908950466328125, 16950118160085960270323673755750390625, 90543986887356385297750500755391437150880164126953125 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS The sequence A234144(n)/A234145(n) is Theta(n, n), as defined by Wolfdieter Lang. LINKS Wolfdieter Lang, Theta(k, n), k-family of rational sequences and limits. FORMULA a(n) = denominator of (2^n*Zeta(n) - Zeta(n) - Zeta(n, n+1/2))/2^n. a(n) = denominator of ((-1/2)^n*(PolyGamma(n-1, 1/2) - PolyGamma(n-1, n+1/2)))/(n-1)!. A234144(n) / A234145(n) ~ 1. MATHEMATICA a[n_] := Sum[1/(2*k-1)^n, {k, 1, n}] // Denominator; Table[a[n], {n, 0, 10}] CROSSREFS Cf. A164655, A164656, A234144 (numerators). Sequence in context: A281538 A335010 A203744 * A291547 A266458 A238120 Adjacent sequences:  A234142 A234143 A234144 * A234146 A234147 A234148 KEYWORD nonn,frac,easy AUTHOR Jean-François Alcover, Dec 20 2013 STATUS approved

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Last modified December 8 08:06 EST 2021. Contains 349594 sequences. (Running on oeis4.)