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A342458
a(n) = gcd(A001615(n), A003415(n)), where A001615 is Dedekind psi, and A003415 is the arithmetic derivative of n.
7
1, 1, 1, 2, 1, 1, 1, 12, 6, 1, 1, 8, 1, 3, 8, 8, 1, 3, 1, 12, 2, 1, 1, 4, 10, 3, 9, 16, 1, 1, 1, 16, 2, 1, 12, 12, 1, 3, 8, 4, 1, 1, 1, 24, 3, 1, 1, 16, 14, 45, 4, 28, 1, 27, 8, 4, 2, 1, 1, 4, 1, 3, 3, 96, 6, 1, 1, 36, 2, 1, 1, 12, 1, 3, 5, 40, 6, 1, 1, 16, 108, 1, 1, 4, 2, 3, 8, 4, 1, 3, 4, 48, 2, 1, 24, 16, 1, 7, 3, 20
OFFSET
1,4
LINKS
FORMULA
a(n) = gcd(A001615(n), A003415(n)).
a(n) = A003557(n) * A342459(n).
a(n) = A003415(n) / A342919(n).
PROG
(PARI)
A001615(n) = if(1==n, n, my(f=factor(n)); prod(i=1, #f~, f[i, 1]^f[i, 2] + f[i, 1]^(f[i, 2]-1))); \\ After code in A001615
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A342458(n) = gcd(A001615(n), A003415(n));
CROSSREFS
Cf. A301939 (gives the positions at which a(n) = A001615(n) = A003415(n)).
Cf. also A175732, A342413, A342915.
Sequence in context: A236938 A079834 A368811 * A358722 A256688 A372326
KEYWORD
nonn
AUTHOR
Antti Karttunen, Mar 28 2021
STATUS
approved