A154887 Number of ways to partition n into distinct reduced fractions i/j with j<=n.

1, 2, 11, 71, 838, 7915, 181443

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Example

a(3) = #{3, 8/3+1/3, 5/2+1/2, 7/3+2/3, 2+1, 2+2/3+1/3, 5/3+4/3, 5/3+1+1/3, 3/2+1+1/2, 3/2+2/3+1/2+1/3, 4/3+1+2/3} = 11. - corrected by Reinhard Zumkeller, Feb 02 2009

Crossrefs

Cf. A154886, A154888, A143270.

Sequence in context: A214692 A186633 A291301 * A371518 A363389 A323842

Adjacent sequences: A154884 A154885 A154886 * A154888 A154889 A154890

Keyword

more,nonn

Author

Reinhard Zumkeller, Jan 17 2009

Status

approved