A277573 a(n) = (1/3)*A277569(n).

1, 3, 5, 6, 7, 9, 11, 13, 15, 17, 18, 19, 21, 23, 25, 27, 29, 30, 31, 33, 35, 36, 37, 39, 41, 42, 43, 45, 47, 49, 51, 53, 54, 55, 57, 59, 61, 63, 65, 66, 67, 69, 71, 73, 75, 77, 78, 79, 81, 83, 85, 87, 89, 90, 91, 93, 95, 97, 99, 101, 102, 103, 105, 107, 108

Offset: 1

Author

Clark Kimberling, Nov 01 2016

Keywords

• nonn
• easy

Comments

From Amiram Eldar, Jan 16 2022: (Start)

Numbers whose 3-adic valuation is not smaller than their 2-adic valuation.

The asymptotic density of this sequence is 3/5. (End)

Links

• Clark Kimberling, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007814, A007949.

Cf. A277568, A277569, A277572, A277574.

Programs

Mathematica

z = 260; a[b_] := Table[Mod[n/b^IntegerExponent[n, b], b], {n, 1, z}]
p[b_, d_] := Flatten[Position[a[b], d]]
p[6, 3]/3
(* second program *)
Select[Range[200], IntegerExponent[#, 3] >= IntegerExponent[#, 2] &] (* Amiram Eldar, Jan 16 2022 *)