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A318830 a(n) = phi(n) - gcd(phi(n), n-1). 4
0, 0, 0, 1, 0, 1, 0, 3, 4, 3, 0, 3, 0, 5, 6, 7, 0, 5, 0, 7, 8, 9, 0, 7, 16, 11, 16, 9, 0, 7, 0, 15, 16, 15, 22, 11, 0, 17, 22, 15, 0, 11, 0, 19, 20, 21, 0, 15, 36, 19, 30, 21, 0, 17, 38, 23, 32, 27, 0, 15, 0, 29, 34, 31, 32, 15, 0, 31, 40, 21, 0, 23, 0, 35, 38, 33, 56, 23, 0, 31, 52, 39, 0, 23, 60, 41, 54, 39, 0, 23, 54, 43 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

LINKS

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

FORMULA

a(n) = A000010(n) - A049559(n) = phi(n) - gcd(phi(n), n-1).

a(n) = A318827(n) - A051953(n).

PROG

(PARI)

A049559(n) = gcd(eulerphi(n), n-1); \\ From A049559.

A318830(n) = (eulerphi(n)-A049559(n));

CROSSREFS

Cf. A000010, A049558, A051953, A318827.

Sequence in context: A072681 A244042 A318840 * A242803 A064460 A108481

Adjacent sequences:  A318827 A318828 A318829 * A318831 A318832 A318833

KEYWORD

nonn

AUTHOR

Antti Karttunen, Sep 09 2018

STATUS

approved

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Last modified October 19 11:00 EDT 2019. Contains 328216 sequences. (Running on oeis4.)