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A074389
a(n) = gcd(n, sigma(n), phi(n)).
6
1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 4, 1, 2, 1, 1, 1, 3, 1, 2, 1, 2, 1, 4, 1, 2, 1, 4, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 6, 1, 4, 3, 2, 1, 4, 1, 1, 1, 2, 1, 6, 1, 8, 1, 2, 1, 4, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 1, 4, 1, 6, 1, 2, 1, 2, 1, 4, 1, 2, 1, 4, 1, 6, 1, 4, 1, 2, 1, 4, 1, 1, 3, 1, 1, 2, 1, 2, 3
OFFSET
1,6
LINKS
FORMULA
a(n) = gcd(n, A000010(n), A000203(n)).
a(n) = gcd(n, A009223(n)). - Antti Karttunen, Sep 07 2018
MATHEMATICA
Table[Apply[GCD, {w, DivisorSigma[1, w], EulerPhi[w]}], {w, 1, 128}]
PROG
(PARI) A074389(n) = gcd([n, sigma(n), eulerphi(n)]); \\ Antti Karttunen, Sep 07 2018
CROSSREFS
In the old definition the erroneously given formula gcd(n, A000005(n), A000010(n)) is now sequence A318459. - Antti Karttunen, Sep 07 2018
Sequence in context: A376758 A304750 A104306 * A353688 A353666 A051119
KEYWORD
nonn
AUTHOR
Labos Elemer, Aug 23 2002
EXTENSIONS
Name corrected by Antti Karttunen, Sep 07 2018
STATUS
approved