A135872 Multiply the positive integers which are coprime to n in order (starting at 1). a(n) is the smallest such partial product that is >= n.

1, 3, 8, 15, 6, 35, 24, 15, 40, 21, 24, 35, 24, 15, 56, 105, 24, 35, 24, 21, 40, 105, 24, 35, 144, 105, 40, 135, 120, 77, 120, 105, 40, 105, 144, 385, 120, 105, 40, 189, 120, 55, 120, 105, 56, 105, 120, 385, 120, 189, 280, 105, 120, 385, 144, 135, 280, 105, 120

Offset

1,2

Links

Table of n, a(n) for n=1..59.

Example

The positive integers which are coprime to 9 begin: 1,2,4,5,7,8,10,11,... Checking the partial products: 1=1, 1*2=2, 1*2*4 = 8, 1*2*4*5 =40,... 40 is the smallest such partial product which is >= 9. So a(9) = 40.

Mathematica

a = {}; For[n = 1, n < 60, n++, p = 1; i = 1; While[p < n, i++; If[GCD[i, n] == 1, p = p*i]]; AppendTo[a, p]]; a (* Stefan Steinerberger, Feb 06 2008 *)

Crossrefs

Cf. A135873.

Sequence in context: A005735 A208436 A297015 * A242245 A045263 A004733

Adjacent sequences: A135869 A135870 A135871 * A135873 A135874 A135875

Keyword

nonn

Author

Leroy Quet, Dec 03 2007

Extensions

More terms from Stefan Steinerberger, Feb 06 2008

Status

approved