A124330 - OEIS

A124330

a(n)= ((d(n) mod phi(n)) +1)th positive integer which is coprime to n, where phi(n) is number of positive integers which are <= n and are coprime to n and d(n) is the number of positive divisors of n.

1, 1, 1, 3, 3, 1, 3, 1, 5, 1, 3, 7, 3, 11, 8, 11, 3, 1, 3, 17, 8, 9, 3, 1, 4, 9, 7, 15, 3, 1, 3, 13, 7, 9, 6, 29, 3, 9, 7, 21, 3, 29, 3, 15, 13, 9, 3, 31, 4, 17, 7, 15, 3, 25, 6, 19, 7, 9, 3, 47, 3, 9, 11, 15, 6, 29, 3, 13, 7, 27, 3, 37, 3, 9, 13, 13, 5, 29, 3, 27, 8, 9, 3, 43, 6, 9, 7, 19, 3, 47, 5

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OFFSET

1,4

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..20000

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) A124330(n) = { my(k=1+(numdiv(n)%eulerphi(n))); for(i=1, oo, if(1==gcd(i, n), k--; if(!k, return(i)))); }; \\ Antti Karttunen, Feb 18 2023

CROSSREFS

Cf. A000005, A000010, A124218, A124331.

Sequence in context: A323626 A133695 A138114 * A055177 A030778 A324078

Adjacent sequences: A124327 A124328 A124329 * A124331 A124332 A124333

KEYWORD

nonn

AUTHOR

Leroy Quet and Ray Chandler, Oct 26 2006

STATUS

approved