A067540 Number of partitions of n in which the sum of reciprocal of parts divides number of parts.

1, 2, 2, 3, 2, 4, 2, 5, 5, 7, 4, 8, 5, 7, 5, 10, 5, 16, 8, 20, 9, 20, 10, 25, 13, 30, 21, 34, 32, 46, 35, 58, 48, 66, 59, 97, 65, 109, 94, 125, 112, 154, 133, 191, 154, 224, 195, 265, 236, 308, 289, 388, 353, 475, 424, 575, 528, 693, 661, 835

Offset

1,2

Links

Chai Wah Wu, Table of n, a(n) for n = 1..147 (n = 1..80 from Sean A. Irvine)

Formula

a(n)=#{n=p_1+p_2+...+p_r : r/sum_{i=1..r} 1/p_i is an integer} where n=p_1+p_2+...+p_r runs over all partitions of n. - Sean A. Irvine, Mar 24 2013

a(n) <= A058360(n) <= A000041(n). - Charles R Greathouse IV, Dec 15 2020

Crossrefs

Cf. A000041.

Sequence in context: A323888 A289435 A328396 * A218701 A305790 A294877

Adjacent sequences: A067537 A067538 A067539 * A067541 A067542 A067543

Keyword

nonn

Author

Naohiro Nomoto, Jan 27 2002

Extensions

More terms from Sean A. Irvine, Mar 24 2013

Status

approved