A155082 Composites k such that the number of prime factors of composite(k) (counted with multiplicity) is composite.

9, 14, 24, 27, 39, 42, 45, 58, 60, 64, 65, 74, 76, 95, 99, 102, 105, 114, 115, 119, 122, 141, 146, 152, 168, 172, 175, 176, 178, 182, 187, 194, 196, 201, 204, 217, 231, 234, 243, 244, 249, 261, 268, 273, 275, 278, 279, 280, 287, 291, 298, 300, 301, 304, 312

Offset

1,1

Links

Muniru A Asiru, Table of n, a(n) for n = 1..10000

Example

9 (composite) is a term because composite(9) = 16 = 2*2*2*2 (4 prime factors);
14 (composite) is a term because composite(14) = 24 = 2*2*2*3 (4 prime factors);
24 (composite) is a term because composite(24) = 36 = 2*2*3*3 (4 prime factors).

Prog

(GAP) A:=Filtered([2..500], n->not IsPrime(n));;
B:=List(List(A, Factors), Length);;
a:=Filtered([1..Length(B)], i->B[i] in A and not IsPrime(i)); # Muniru A Asiru, Feb 10 2019

Crossrefs

Cf. A000040, A002808, A001222.

Sequence in context: A151915 A100263 A371059 * A161547 A104812 A329751

Adjacent sequences: A155079 A155080 A155081 * A155083 A155084 A155085

Keyword

nonn

Author

Juri-Stepan Gerasimov, Jan 20 2009

Extensions

Corrected (45 inserted, 109 removed, 146 replaced with 146 etc.) by R. J. Mathar, May 05 2010

Status

approved