A367018 - OEIS

A367018

Composite squarefree k that are not divisible by 6.

10, 14, 15, 21, 22, 26, 33, 34, 35, 38, 39, 46, 51, 55, 57, 58, 62, 65, 69, 70, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 105, 106, 110, 111, 115, 118, 119, 122, 123, 129, 130, 133, 134, 141, 142, 143, 145, 146, 154, 155, 158, 159, 161, 165, 166, 170, 177, 178, 182

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OFFSET

1,1

COMMENTS

The asymptotic density of this sequence is 1/(2*Pi^2). - Amiram Eldar, Jan 20 2024

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

FORMULA

Intersection of A047253 and A120944 = { k : Omega(k) > omega(k) = 1, k mod 6 != 0 }.

EXAMPLE

70 is in this sequence since it is composite and squarefree but not divisible by 6. It does not appear in A006881 since it is the product of 3 primes.

MATHEMATICA

Select[Range[180], And[SquareFreeQ[#], CompositeQ[#], Mod[#, 6] != 0] &]

CROSSREFS

Cf. A047253, A120944, A367455.

Sequence in context: A100929 A307980 A366413 * A087247 A307507 A171156

Adjacent sequences: A367015 A367016 A367017 * A367019 A367020 A367021

KEYWORD

nonn,easy

AUTHOR

Michael De Vlieger, Jan 15 2024

STATUS

approved