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 A297086 a(n) = 1 if gcd(n, phi(n)) == 1 otherwise 0. 4
 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 a(n) = [gcd(n,phi(n)) = 1], where [ ] is the Iverson Bracket. - Wesley Ivan Hurt, Jan 20 2024 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. MATHEMATICA Table[KroneckerDelta[GCD[n, EulerPhi[n]], 1], {n, 100}] (* Wesley Ivan Hurt, Jan 20 2024 *) PROG (PARI) {a(n) = gcd(n, eulerphi(n))==1} CROSSREFS Cf. A000010 (phi), A003277, A013929, A061091. Sequence in context: A080339 A294905 A353787 * A349920 A369253 A167752 Adjacent sequences: A297083 A297084 A297085 * A297087 A297088 A297089 KEYWORD nonn,easy AUTHOR Seiichi Manyama, Dec 25 2017 STATUS approved

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Last modified July 24 12:13 EDT 2024. Contains 374583 sequences. (Running on oeis4.)