A079712 Numbers m such that bigomega(m) = 3*omega(m).

1, 8, 27, 96, 125, 144, 160, 216, 224, 324, 343, 352, 400, 416, 486, 544, 608, 736, 784, 928, 992, 1000, 1184, 1215, 1312, 1331, 1376, 1504, 1696, 1701, 1888, 1920, 1936, 1952, 2025, 2144, 2197, 2272, 2336, 2500, 2528, 2656, 2673, 2688, 2704, 2744, 2848

Offset: 1

Author

Benoit Cloitre, Jan 31 2003

Keywords

• nonn

Comments

A cube k is a term iff k belongs to A062838; in this case, k = p_1^3 * p_2^3 *...* p_r^3 and bigomega(k) = 3*omega(k) = 3*r. - Bernard Schott, May 09 2022

Links

• Enrique Pérez Herrero, Table of n, a(n) for n = 1..2000

Crossrefs

Cf. A067801, A062838 (subsequence of cubes).

Programs

Mathematica

Select[Range[3000], PrimeOmega[#] == 3*PrimeNu[#] &] (* Amiram Eldar, Jun 29 2022 *)

PARI

is(n)=my(f=factor(n)[,2]); vecsum(f)==3*#f \\ Charles R Greathouse IV, Oct 16 2015