OFFSET
1,3
COMMENTS
a(n) = 1 for n in A127724.
LINKS
Michel Marcus, Table of n, a(n) for n = 1..10000
László Tóth, A survey of the alternating sum-of-divisors function, arXiv:1111.4842 [math.NT], 2011-2014.
MATHEMATICA
(* b = A209369 *) b[n_] := n*DivisorSum[n, LiouvilleLambda[#]/# &];
a[n_] := Numerator[b[n]/n];
Array[a, 100] (* Jean-François Alcover, Dec 04 2017 *)
PROG
(PARI) rhope(p, e) = my(s=1); for(i=1, e, s=s*p + (-1)^i); s;
rho(n) = my(f=factor(n)); prod(i=1, #f~, rhope(f[i, 1], f[i, 2]));
a(n) = numerator(rho(n)/n);
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Michel Marcus, Nov 06 2017
STATUS
approved