A120842 a(n) = the (number of positive divisors of n)th positive integer which is coprime to n.

1, 3, 2, 5, 2, 11, 2, 7, 4, 9, 2, 17, 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

Offset

1,2

Links

Paolo P. Lava, Table of n, a(n) for n = 1..1000

Example

12 has 6 positive divisors. 1,5,7,11,13,17,19,23,25...is the sequence of positive integers which are coprime to 12. 17 is the 6th of these integers, so a(12) = 17.

Crossrefs

Cf. A000005.

Sequence in context: A226172 A281006 A046227 * A319044 A230820 A324549

Adjacent sequences: A120839 A120840 A120841 * A120843 A120844 A120845

Keyword

nonn

Author

Leroy Quet, Aug 18 2006

Extensions

Extended by Ray Chandler, Aug 22 2006

Status

approved