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A348979
Denominator of ratio A332993(n) / sigma(n).
4
1, 1, 1, 1, 1, 6, 1, 1, 1, 9, 1, 14, 1, 12, 8, 1, 1, 39, 1, 7, 32, 18, 1, 30, 1, 21, 1, 28, 1, 24, 1, 1, 16, 27, 48, 91, 1, 30, 56, 45, 1, 96, 1, 14, 13, 36, 1, 62, 1, 31, 24, 49, 1, 60, 72, 60, 80, 45, 1, 56, 1, 48, 26, 1, 84, 48, 1, 21, 32, 144, 1, 195, 1, 57, 62, 70, 96, 168, 1, 31, 1, 63, 1, 224, 108, 66, 40, 90
OFFSET
1,6
COMMENTS
See comments in A348978.
FORMULA
a(n) = A000203(n) / A348977(n) = A000203(n) / gcd(A000203(n), A332993(n)).
MATHEMATICA
f[n_] := n/FactorInteger[n][[1, 1]]; g[1] = 1; g[n_] := g[n] = n + g[f[n]]; a[n_] := Denominator[g[n]/DivisorSigma[1, n]]; Array[a, 100] (* Amiram Eldar, Nov 06 2021 *)
PROG
(PARI)
A332993(n) = if(1==n, n, n + A332993(n/vecmin(factor(n)[, 1])));
A348979(n) = { my(s=sigma(n)); (s/gcd(s, A332993(n))); };
CROSSREFS
Cf. A000203, A332993, A333783, A348977, A348978 (numerators).
Cf. also A348988, A348989.
Sequence in context: A063919 A308135 A072815 * A080304 A340677 A340679
KEYWORD
nonn,frac
AUTHOR
Antti Karttunen, Nov 06 2021
STATUS
approved