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A297086 a(n) = 1 if gcd(n, phi(n)) == 1 otherwise 0. 2
1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

Characteristic function of A003277. - Iain Fox, Dec 25 2017

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Totient Function

FORMULA

For even n > 2, a(n) = 0. - Iain Fox, Dec 25 2017

If n is in A013929 then a(n) = 0. - David A. Corneth, Dec 25 2017

EXAMPLE

gcd(5, phi(5)) = gcd(5, 4) = 1, so a(5) = 1.

gcd(6, phi(6)) = gcd(6, 2) = 2, so a(6) = 0.

PROG

(PARI) {a(n) = gcd(n, eulerphi(n))==1}

CROSSREFS

Cf. A000010 (phi), A003277, A013929, A061091.

Sequence in context: A267133 A080339 A294905 * A167752 A240025 A100923

Adjacent sequences:  A297083 A297084 A297085 * A297087 A297088 A297089

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Dec 25 2017

STATUS

approved

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Last modified April 24 20:29 EDT 2019. Contains 322446 sequences. (Running on oeis4.)