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 A068237 Numerators of arithmetic derivative of 1/n: -A003415(n)/n^2. 3
 0, -1, -1, -1, -1, -5, -1, -3, -2, -7, -1, -1, -1, -9, -8, -1, -1, -7, -1, -3, -10, -13, -1, -11, -2, -15, -1, -2, -1, -31, -1, -5, -14, -19, -12, -5, -1, -21, -16, -17, -1, -41, -1, -3, -13, -25, -1, -7, -2, -9, -20, -7, -1, -1, -16, -23, -22, -31, -1, -23 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..10000 MAPLE d:= n-> n*add(i[2]/i[1], i=ifactors(n)[2]): a:= n-> numer(-d(n)/n^2): seq(a(n), n=1..80);  # Alois P. Heinz, Jun 07 2015 MATHEMATICA d[n_] := If[n < 2, 0, n Sum[f[[2]]/f[[1]], {f, FactorInteger[n]}]]; a[n_] := Numerator[-d[n]/n^2]; Array[a, 80] (* Jean-François Alcover, Mar 12 2019 *) CROSSREFS Cf. A003415, A068238 (denominators). Sequence in context: A055515 A215010 A136744 * A083345 A087262 A082343 Adjacent sequences:  A068234 A068235 A068236 * A068238 A068239 A068240 KEYWORD sign,frac,look AUTHOR Reinhard Zumkeller, Feb 23 2002 STATUS approved

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Last modified December 11 07:47 EST 2019. Contains 329914 sequences. (Running on oeis4.)