

A124218


a(n) is the mth positive integer which is coprime to n, where phi(n) is number of positive integers which are <= n and are coprime to n, d(n) is the number of positive divisors of n and m = phi(n) if phi(n)d(n), else m = d(n) mod phi(n).


3



1, 1, 2, 1, 2, 5, 2, 7, 4, 9, 2, 5, 2, 9, 7, 9, 2, 17, 2, 13, 5, 7, 2, 23, 3, 7, 5, 13, 2, 29, 2, 11, 5, 7, 4, 25, 2, 7, 5, 19, 2, 25, 2, 13, 11, 7, 2, 29, 3, 13, 5, 11, 2, 23, 4, 17, 5, 7, 2, 43, 2, 7, 10, 13, 4, 25, 2, 11, 5, 23, 2, 35, 2, 7, 11, 11, 4, 25, 2, 23, 7, 7, 2, 41, 4, 7, 5, 17, 2, 43, 4
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OFFSET

1,3


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..16384


MATHEMATICA

f[n_] := Block[{k = 0, m = Mod[Length[Divisors[n]], EulerPhi[n], 1]}, While[m > 0, k++; While[GCD[n, k] > 1, k++ ]; m; ]; k]; Table[f[n], {n, 100}] (* Ray Chandler, Oct 26 2006 *)


PROG

(PARI) A124218(n) = { my(d=numdiv(n), t=eulerphi(n), m=if(!(d%t), t, (d%t))); for(k=1, oo, if(1==gcd(k, n), m; if(!m, return(k)))); }; \\ Antti Karttunen, Mar 30 2021


CROSSREFS

Cf. A000005, A000010, A124219, A124330.
Sequence in context: A064192 A284553 A216913 * A025165 A345278 A212431
Adjacent sequences: A124215 A124216 A124217 * A124219 A124220 A124221


KEYWORD

nonn


AUTHOR

Leroy Quet, Oct 19 2006


EXTENSIONS

Edited and extended by Ray Chandler, Oct 26 2006


STATUS

approved



