A124219 - OEIS

A124219

a(n)= m-th positive divisor of 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 = d(n) if d(n)|phi(n), else m = phi(n) mod d(n).

1, 1, 3, 2, 5, 2, 7, 8, 9, 10, 11, 4, 13, 2, 15, 4, 17, 18, 19, 2, 21, 2, 23, 24, 5, 26, 3, 28, 29, 30, 31, 8, 33, 34, 35, 3, 37, 2, 39, 40, 41, 6, 43, 2, 45, 2, 47, 8, 49, 2, 51, 52, 53, 2, 55, 56, 57, 58, 59, 4, 61, 2, 63, 8, 65, 6, 67, 2, 69, 70, 71, 72, 73, 74, 15, 76, 77, 78, 79, 2

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OFFSET

1,3

LINKS

Table of n, a(n) for n=1..80.

MATHEMATICA

f[n_] := Block[{d = Divisors[n]}, d[[Mod[EulerPhi[n], Length[d], 1]]]]; Table[f[n], {n, 90}] (* Ray Chandler, Oct 26 2006 *)

CROSSREFS

Cf. A000005, A000010, A124218, A124331.

Sequence in context: A086571 A350509 A133945 * A103833 A226172 A281006

Adjacent sequences: A124216 A124217 A124218 * A124220 A124221 A124222

KEYWORD

nonn

AUTHOR

Leroy Quet, Oct 19 2006

EXTENSIONS

Edited and extended by Ray Chandler, Oct 26 2006

STATUS

approved