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 A099320 Denominators of an approximation of Riemann to pi(n). 2
 1, 2, 2, 4, 1, 2, 1, 3, 12, 3, 6, 3, 6, 3, 3, 24, 12, 12, 12, 12, 12, 12, 12, 12, 6, 12, 4, 12, 12, 12, 12, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 15, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 5, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Edwards, p. 22, calls this J(n). REFERENCES J. C. Lagarias and A. M. Odlyzko, Computing pi(x): an analytic method, J. Algorithms, 8 (2087), 173-191. H. M. Edwards, Riemann's Zeta Function, Academic Press, NY, 1974. LINKS T. D. Noe, Table of n, a(n) for n=1..10000 EXAMPLE 0, 1/2, 3/2, 9/4, 3, 7/2, 4, 14/3, 61/12, 16/3, 35/6, 19/3,... MATHEMATICA f[n_] := Module[{i, m, p, t1, t2}, t1 = 0; For[i = 1, i <= n, i++, p = Prime[i]; If[p > n, Break[]]; For[m = 1, m <= n, m++, If[p^m > n, Break[]]; If[n == p^m, t2 = 1/(2m), t2 = 1/m]; t1 = t1 + t2]]; t1]; Table[f[n] // Denominator, {n, 1, 100}] (* Jean-François Alcover, Apr 02 2023, after Maple code in A099319 *) CROSSREFS See A099319 for definition and program. Sequence in context: A143485 A181633 A245204 * A206714 A230442 A034951 Adjacent sequences: A099317 A099318 A099319 * A099321 A099322 A099323 KEYWORD nonn,frac AUTHOR N. J. A. Sloane, Nov 17 2004 STATUS approved

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Last modified July 15 09:15 EDT 2024. Contains 374324 sequences. (Running on oeis4.)