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A068237
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Numerators of arithmetic derivative of 1/n: -A003415(n)/n^2.
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3
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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
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OFFSET
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1,6
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LINKS
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MAPLE
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d:= n-> n*add(i[2]/i[1], i=ifactors(n)[2]):
a:= n-> numer(-d(n)/n^2):
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MATHEMATICA
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d[n_] := If[n < 2, 0, n Sum[f[[2]]/f[[1]], {f, FactorInteger[n]}]];
a[n_] := Numerator[-d[n]/n^2];
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PROG
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(Python)
from fractions import Fraction
from sympy import factorint
def A068237(n): return -Fraction(sum((Fraction(e, p) for p, e in factorint(n).items())), n).numerator # Chai Wah Wu, Nov 03 2022
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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