A121061 Numbers k such that k-th partition number A000041(k) is a 3-almost prime (A014612).

9, 10, 16, 18, 20, 22, 25, 29, 31, 34, 37, 42, 45, 48, 50, 56, 57, 60, 63, 69, 71, 72, 73, 83, 85, 91, 101, 102, 112, 113, 114, 119, 139, 144, 148, 151, 155, 156, 172, 175, 183, 185, 190, 192, 195, 202, 208, 217, 238, 242, 244, 245, 247, 256, 257, 272, 275, 291, 293

Offset

1,1

Links

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

Formula

A000041(a(n)) in A014612.

Example

a(1) = 9 because P(9) = 30 = 2 * 3 * 5.
a(2) = 10 because P(10) = 42 = 2 * 3 * 7.
a(3) = 16 because P(16) = 231 = 3 * 7 * 11.

Mathematica

Select[Range[300], PrimeOmega[PartitionsP[#]]==3&] (* James C. McMahon, Oct 12 2024 *)

Crossrefs

Cf. A000041, A046063, A065728, A065729.

Sequence in context: A105742 A105834 A280846 * A106690 A173015 A045568

Adjacent sequences: A121058 A121059 A121060 * A121062 A121063 A121064

Keyword

easy,nonn

Author

Jonathan Vos Post, Aug 09 2006

Extensions

112 and 113 inserted by R. J. Mathar, Dec 22 2010

Status

approved