

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
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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



