A167207 - OEIS

A167207

Numbers that are not divisible by a smaller number that is a square greater than 1.

1, 2, 3, 4, 5, 6, 7, 9, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 25, 26, 29, 30, 31, 33, 34, 35, 37, 38, 39, 41, 42, 43, 46, 47, 49, 51, 53, 55, 57, 58, 59, 61, 62, 65, 66, 67, 69, 70, 71, 73, 74, 77, 78, 79, 82, 83, 85, 86, 87, 89, 91, 93, 94, 95, 97, 101, 102, 103, 105, 106

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

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

EXAMPLE

14 is a term because there is no square strictly between 1 and 14 that divides 14.

MATHEMATICA

q[n_] := Module[{e = FactorInteger[n][[;; , 2]]}, e == {2} || AllTrue[e, # == 1 &]]; Select[Range[120], q] (* Amiram Eldar, Jul 02 2025 *)

PROG

(PARI) isok(n) = {fordiv (n, d, if (issquare(d) && (d>1) && (d<n), return (0))); return (1); } \\ Michel Marcus, Jun 08 2013

CROSSREFS