login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A171241 Numbers k such that A169611(k) = 3. 1
8, 12, 18, 27, 40, 56, 60, 84, 88, 90, 104, 126, 132, 135, 136, 152, 156, 184, 189, 198, 200, 204, 228, 232, 234, 248, 276, 280, 296, 297, 300, 306, 328, 342, 344, 348, 351, 372, 376, 392, 414, 420, 424, 440, 444, 450, 459, 472, 488, 492, 513, 516, 520, 522 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Numbers of the form k*m where k is in {8, 12, 18, 27} and gcd(m, 6) = 1. - David A. Corneth, Aug 31 2019
The asymptotic density of this sequence is 65/648. - Amiram Eldar, Jan 16 2022
LINKS
MATHEMATICA
aQ[n_] := Plus @@ Last /@ Select[FactorInteger@n, 1 < #[[1]] < 4 &] == 3; Select[Range[522], aQ] (* Amiram Eldar, Aug 31 2019 after Robert G. Wilson v at A169611 *)
PROG
(PARI) is(n) = bigomega(gcd(n, 1296)) == 3 \\ David A. Corneth, Aug 31 2019
CROSSREFS
Sequence in context: A028393 A066681 A276403 * A120137 A274951 A364776
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Corrected (200, 232, 280 inserted) and extended by R. J. Mathar, Jun 04 2010
Name corrected by Amiram Eldar, Aug 31 2019
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)