A164596 Squarefree positive integers n where at least one prime divisor of n is < the product of the smaller prime divisors of n.

30, 70, 105, 154, 165, 182, 195, 210, 231, 273, 286, 330, 357, 374, 385, 390, 399, 418, 429, 442, 455, 462, 494, 510, 546, 561, 570, 595, 598, 627, 646, 663, 665, 690, 714, 715, 741, 759, 770, 782, 798, 805, 858, 870, 874, 897, 910, 930, 935, 957, 966, 969

Offset

1,1

Comments

Each term is divisible by at least 3 primes.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

70 is factored as 2*5*7. Since 2*5 > 7, then 70 is in this sequence.

Mathematica

aQ[n_] := SquareFreeQ[n] && Module[{p = FactorInteger[n][[;; , 1]], ans = False}, Do[If[p[[k]] < Times @@ p[[1 ;; k-1]], ans = True; Break[]], {k, 1, Length[p]}]; ans]; Select[Range[1000], aQ] (* Amiram Eldar, Oct 06 2019 *)

Crossrefs

Sequence in context: A112343 A182996 A325378 * A295102 A131647 A301900

Adjacent sequences: A164593 A164594 A164595 * A164597 A164598 A164599

Keyword

nonn

Author

Leroy Quet, Aug 17 2009

Extensions

More terms from Max Alekseyev, Sep 04 2009

Status

approved