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A348028
Greatest common divisor of A003415 (arithmetic derivative) and sigma, the sum of divisors function.
1
1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 4, 1, 3, 8, 1, 1, 3, 1, 6, 2, 1, 1, 4, 1, 3, 1, 8, 1, 1, 1, 1, 2, 1, 12, 1, 1, 3, 8, 2, 1, 1, 1, 12, 39, 1, 1, 4, 1, 3, 4, 14, 1, 3, 8, 4, 2, 1, 1, 4, 1, 3, 1, 1, 6, 1, 1, 18, 2, 1, 1, 39, 1, 3, 1, 20, 6, 1, 1, 2, 1, 1, 1, 4, 2, 3, 8, 20, 1, 3, 4, 24, 2, 1, 24, 4, 1, 1, 3, 7, 1, 1, 1, 2, 1
OFFSET
1,8
FORMULA
a(n) = gcd(A000203(n), A003415(n)).
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A348028(n) = gcd(sigma(n), A003415(n));
CROSSREFS
Cf. also A342413, A342458, A343226.
Sequence in context: A305439 A270825 A364096 * A375011 A059619 A098950
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 25 2021
STATUS
approved