A331177 - OEIS

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A331177

Number of values of k, 1 <= k <= n, with A319677(k) = A319677(n), where A319677(n) = n/gcd(n, uphi(n)), and uphi is unitary totient function (A047994).

1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 2, 1, 3, 3, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 3, 1, 1, 4, 1, 1, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 3, 2, 3, 2, 1, 4, 1, 2, 1, 1, 1, 2, 1, 3, 1, 2, 1, 3, 1, 2, 3, 1, 1, 5, 1, 3, 1, 2, 1, 5, 1, 2, 1, 1, 1, 2, 1, 1, 3, 2, 1, 1, 1, 2, 1, 4, 1, 2, 1, 1, 3

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OFFSET

1,6

COMMENTS

Ordinal transform of A319677.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

PROG

(PARI)

up_to = 65537;

ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om, invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om, invec[i], (1+pt))); outvec; };

A047994(n) = { my(f=factor(n)); prod(i=1, #f~, (f[i, 1]^f[i, 2])-1); };

A319677(n) = n/gcd(n, A047994(n));

v331177 = ordinal_transform(vector(up_to, n, A319677(n)));

A331177(n) = v331177[n];

CROSSREFS

Cf. A047994, A319677.

Cf. also A330739, A331175.

Sequence in context: A323172 A327403 A247371 * A173751 A126864 A348928

Adjacent sequences: A331174 A331175 A331176 * A331178 A331179 A331180

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jan 11 2020

STATUS

approved