A088380 Numbers not exceeding the cube of their smallest prime factor.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 35, 37, 41, 43, 47, 49, 53, 55, 59, 61, 65, 67, 71, 73, 77, 79, 83, 85, 89, 91, 95, 97, 101, 103, 107, 109, 113, 115, 119, 121, 125, 127, 131, 133, 137, 139, 143, 149, 151, 157, 161, 163, 167, 169

Offset: 1

Author

Reinhard Zumkeller, Sep 28 2003

Keywords

• nonn

Comments

a(n) <= A020639(a(n))^3 = A088378(a(n)); complement of A088381;

a(n) < A088381(k) for n <= 28, a(n) > A088381(k) for n > 28.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000430, A088382, A020639, A088378, A088381.

Positions of numbers less than 4 in A307908.

Programs

Haskell

a088380 n = a088382_list !! (n-1)
a088380_list = [x | x <- [1..], x <= a020639 x ^ 3]
-- Reinhard Zumkeller, Feb 06 2015

Mathematica

Select[Range[200],#<=FactorInteger[#][[1,1]]^3&] (* Harvey P. Dale, Apr 28 2022 *)