A063745 Even numbers with an even number of prime factors (counted with multiplicity).

4, 6, 10, 14, 16, 22, 24, 26, 34, 36, 38, 40, 46, 54, 56, 58, 60, 62, 64, 74, 82, 84, 86, 88, 90, 94, 96, 100, 104, 106, 118, 122, 126, 132, 134, 136, 140, 142, 144, 146, 150, 152, 156, 158, 160, 166, 178, 184, 194, 196, 198, 202, 204, 206, 210, 214, 216, 218, 220

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Example

a(2)=6, which is even with even number of prime factors, i.e., 2.

Mathematica

Select[2*Range[200], EvenQ[PrimeOmega[#]]&] (* Harvey P. Dale, Mar 07 2015 *)

Prog

(PARI) isok(k) = { k%2==0 && bigomega(k)%2 == 0 } \\ Harry J. Smith, Aug 29 2009

Crossrefs

Intersection of A028260 and A005843.

Cf. A046337.

Sequence in context: A310583 A298784 A241975 * A123666 A095305 A362416

Adjacent sequences: A063742 A063743 A063744 * A063746 A063747 A063748

Keyword

nonn,changed

Author

Shyam Sunder Gupta, Feb 16 2002

Status

approved