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 A231327 Denominator of rational component of zeta(4n)/zeta(2n). 1
 1, 15, 105, 675675, 34459425, 16368226875, 218517792968475, 30951416768146875, 694097901592400930625, 23383376494609715287281703125, 2289686345687357378035370971875, 219012470258383844016431785453125, 4791965046290912124048163518904807546875 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Denominator of a close variant of Euler's infinite prime product zeta(2n) =  prod_{k>=1} (prime(k)^(2n))/(prime(k)^(2n)-1), namely with all minus signs changed into plus, as follows: zeta(4n)/zeta(2n) =  prod_{k>=1} prime(k)^(2n))/(prime(k)^(2n)+1). For a detailed account of the results in question, including proof and relation to the zeta function, see the PDF file submitted as supporting material in A231273. The reference to Apostol below is a discussion of the equivalence of 1) zeta(2s)/zeta(s) and 2) a related infinite prime product, that is, prod_{sigma>1} (prime(n)^(s)/(prime(n)^(s) + 1), with s being a complex variable such that s = sigma + i*t where sigma and t are real (following Riemann), using a type of proof different from the one posted below involving zeta(4n)/zeta(2n). - Leo Depuydt, Nov 22 2013 Denominator of B(4*n)*4^n*(2*n)!/(B(2*n)*(4*n)!) where B(n) are the Bernoulli numbers (see A027641 and A027642). - Robert Israel, Aug 22 2014 REFERENCES T. M. Apostol, Introduction to Analytic Number Theory, Springer, 1976, p. 231. Leo Depuydt, The Prime Sequence: Demonstrably Highly Organized While Also Opaque and Incomputable-With Remarks on Riemann's Hypothesis, Partition, Goldbach's Conjecture, ..., Advances in Pure Mathematics, 4 (No. 8, 2014), 400-466. LINKS MAPLE seq(denom(bernoulli(4*n)*4^n*(2*n)!/(bernoulli(2*n)*(4*n)!)), n=0..100); # Robert Israel, Aug 22 2014 MATHEMATICA Denominator[Table[Zeta[4 n]/Zeta[2 n], {n, 0, 15}]] (* T. D. Noe, Nov 15 2013 *) CROSSREFS Cf. A231273 (the corresponding numerator). Cf. A114362 and A114363 (closely related results). Cf. A001067, A046968, A046988, A098087, A141590, and A156036 (same number sequence as found in numerator, though in various transformations (alternation of sign, intervening numbers, and so on)). Cf. A027641 and A027642. Sequence in context: A077261 A012507 A143727 * A041426 A278781 A275644 Adjacent sequences:  A231324 A231325 A231326 * A231328 A231329 A231330 KEYWORD nonn,frac AUTHOR Leo Depuydt, Nov 07 2013 STATUS approved

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Last modified July 31 08:59 EDT 2021. Contains 346369 sequences. (Running on oeis4.)