A200511 Numbers n with omega(n)=2 and bigomega(n)>2, where omega=A001221=number of distinct prime factors, bigomega=A001222=prime factors counted with multiplicity.

12, 18, 20, 24, 28, 36, 40, 44, 45, 48, 50, 52, 54, 56, 63, 68, 72, 75, 76, 80, 88, 92, 96, 98, 99, 100, 104, 108, 112, 116, 117, 124, 135, 136, 144, 147, 148, 152, 153, 160, 162, 164, 171, 172, 175, 176, 184, 188, 189, 192, 196, 200, 207, 208, 212, 216, 224, 225, 232, 236

Offset

1,1

Comments

Equivalently, numbers of the form n=p^k*q^m where k,m>0, k+m>2 and p,q prime.

It appears that this is equal to A123711.

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[240], PrimeNu[#] == 2 && PrimeOmega[#] > 2 &] (* Jean-François Alcover, Jun 29 2013 *)

Prog

(PARI) for(n=1, 999, bigomega(n)>2 & omega(n)==2 & print1(n", "))

Crossrefs

Cf. A200521, A178212.

Sequence in context: A342973 A126706 A123711 * A370409 A363101 A369516

Adjacent sequences: A200508 A200509 A200510 * A200512 A200513 A200514

Keyword

nonn

Author

M. F. Hasler, Feb 09 2012

Status

approved