OFFSET
1,2
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-> denom(-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_] := Denominator[-d[n]/n^2];
Array[a, 80] (* Jean-François Alcover, Mar 12 2019 *)
PROG
(Python)
from fractions import Fraction
from sympy import factorint
def A068238(n): return Fraction(sum((Fraction(e, p) for p, e in factorint(n).items())), n).denominator # Chai Wah Wu, Nov 03 2022
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Reinhard Zumkeller, Feb 23 2002
STATUS
approved