A359159 Numbers whose odd part is squarefree and the number of prime factors (with multiplicity) is odd.

2, 3, 5, 7, 8, 11, 12, 13, 17, 19, 20, 23, 28, 29, 30, 31, 32, 37, 41, 42, 43, 44, 47, 48, 52, 53, 59, 61, 66, 67, 68, 70, 71, 73, 76, 78, 79, 80, 83, 89, 92, 97, 101, 102, 103, 105, 107, 109, 110, 112, 113, 114, 116, 120, 124, 127, 128, 130, 131, 137, 138, 139, 148, 149, 151, 154, 157, 163, 164, 165

Offset

1,1

Comments

The asymptotic density of this sequence is 4/Pi^2 (A185199). - Amiram Eldar, Jan 18 2023

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[200], OddQ[PrimeOmega[#]] && SquareFreeQ[#/2^IntegerExponent[#, 2]] &] (* Amiram Eldar, Jan 18 2023 *)

Prog

(PARI) isA359159(n) = A359158(n);

Crossrefs

Intersection of A026424 and A122132.

Setwise difference A122132 \ A359157.

Positions of negative terms in A355689.

Cf. A166486, A185199, A359158 (characteristic function).

Sequence in context: A141832 A066680 A346635 * A298865 A211777 A189299

Adjacent sequences: A359156 A359157 A359158 * A359160 A359161 A359162

Keyword

nonn

Author

Antti Karttunen, Dec 20 2022

Status

approved