The On-Line Encyclopedia of Integer Sequences (OEIS)

A373377 revision #2

A373377

a(n) = gcd(A059975(n), A083345(n)), where A059975 is fully additive with a(p) = p-1, and A083345 is the numerator of the fully additive function with a(p) = 1/p.

0, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 4, 1, 1, 2, 2, 1, 1, 1, 6, 2, 1, 1, 1, 2, 1, 1, 8, 1, 1, 1, 5, 2, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 12, 1, 1, 1, 1, 2, 9, 2, 14, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 18, 2, 1, 1, 1, 1, 1, 1, 20, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 24, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1

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OFFSET

1,8

LINKS

Table of n, a(n) for n=1..105.

PROG

(PARI)

A059975(n) = { my(f = factor(n)); sum(i = 1, #f~, f[i, 2]*(f[i, 1] - 1)); };

A083345(n) = { my(f=factor(n)); numerator(vecsum(vector(#f~, i, f[i, 2]/f[i, 1]))); };

A373377(n) = gcd(A059975(n), A083345(n));

CROSSREFS

Cf. A059975, A083345.