A071814 Numbers k such that the number of 1's in the binary representation of k equals bigomega(k), the number of prime divisors of k (counted with multiplicity).

2, 6, 9, 10, 28, 33, 34, 42, 44, 50, 52, 54, 60, 65, 70, 76, 90, 98, 129, 135, 138, 148, 150, 156, 164, 184, 198, 204, 210, 225, 228, 232, 261, 266, 268, 273, 290, 292, 294, 297, 306, 308, 322, 330, 340, 344, 385, 388, 390, 405, 424, 440, 468, 486, 496, 504

Offset: 1

Author

Jason Earls, Jun 07 2002

Keywords

• easy
• nonn

Comments

A115156 is a subsequence: A001222(A115156(n)) = A000120(A115156(n)) = n. - Reinhard Zumkeller, Jan 14 2006

Examples

			232 is a term because 232 = 11101000_2 and 232 = 2^3*29.
		

Links

• Ivan Neretin, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000120, A001222, A071594, A115156.

Programs

Mathematica

fQ[n_] := Count[IntegerDigits[n, 2], 1] == Plus @@ Last /@ FactorInteger@n; Select[ Range@517, fQ[ # ] &] (* Robert G. Wilson v, Jan 18 2006 *)
Select[Range[600],Count[IntegerDigits[#,2],1]==PrimeOmega[#]&] (* Harvey P. Dale, Mar 07 2019 *)