login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A330729 Numbers n that are divisible by all integers less than or equal to the cube root of n. 0
1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 30, 36, 42, 48, 54, 60, 72, 84, 96, 108, 120, 180, 240, 300, 420 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..32.

EXAMPLE

42 appears because the cube root of 42 is approximately 3.48 and 42 is divisible by 3, 2, and 1 (all positive integers less than 3.48).

MATHEMATICA

Select[Range[1000], Divisible[#, LCM @@ Range @ Floor @ Surd[#, 3]] &] (* Amiram Eldar, Dec 28 2019 *)

PROG

(MAGMA) [k: k in [1..500]|forall{m:m in [1..Floor(k^(1/3))]|k mod m eq 0}]; // Marius A. Burtea, Dec 31 2019

(PARI) is(k) = {my(m=sqrtnint(k, 3)); sum(i=1, m, Mod(k, i)==0) == m; } \\ Jinyuan Wang, Dec 31 2019

CROSSREFS

Cf. A003102.

Sequence in context: A080750 A113768 A122936 * A118729 A008726 A302834

Adjacent sequences:  A330726 A330727 A330728 * A330730 A330731 A330732

KEYWORD

nonn,fini,full

AUTHOR

Eric Fox, Dec 28 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 26 01:49 EDT 2021. Contains 346294 sequences. (Running on oeis4.)