A046340 Odd composite numbers with an odd number of prime factors (counted with multiplicity).

27, 45, 63, 75, 99, 105, 117, 125, 147, 153, 165, 171, 175, 195, 207, 231, 243, 245, 255, 261, 273, 275, 279, 285, 325, 333, 343, 345, 357, 363, 369, 385, 387, 399, 405, 423, 425, 429, 435, 455, 465, 475, 477, 483, 507, 531, 539, 549, 555, 561, 567, 575

Offset: 1

Author

Patrick De Geest, Jun 15 1998

Keywords

• nonn

Links

• John Cerkan, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A046339, A046341.

Programs

Mathematica

Select[Range[3,699,2],OddQ[Total[Transpose[FactorInteger[#]][[2]]]] && !PrimeQ[#]&] (* Harvey P. Dale, Dec 09 2010 *)
Select[Range[3,699,2],CompositeQ[#]&&OddQ[PrimeOmega[#]]&] (* Harvey P. Dale, Jun 18 2024 *)

Extensions

Name (description) modified by Harvey P. Dale, Dec 09 2010