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A052485 Weak numbers (i.e., not powerful (1)): there is a prime p where p|n is true but p^2|n is not true. 14
2, 3, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 26, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 82, 83, 84 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A112526(a(n)) = 0. - Reinhard Zumkeller, Sep 16 2011

LINKS

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

FORMULA

a(n) ~ n. - Charles R Greathouse IV, Jul 19 2012

MATHEMATICA

Select[Range[1000], Min[FactorInteger[#][[All, 2]]] <= 1 &] (* Geoffrey Critzer, Feb 11 2015 *)

PROG

(Haskell)

a052485 n = a052485_list !! (n-1)

a052485_list = filter ((== 0) . a112526) [1..]

-- Reinhard Zumkeller, Sep 16 2011

(PARI) is(n)=n>1 && vecmin(factor(n)[, 2])==1 \\ Charles R Greathouse IV, Mar 19 2014

(PARI) is(n)=!ispowerful(n) \\ Charles R Greathouse IV, Sep 18 2015

CROSSREFS

Cf. A001694. Not the same as A007916.

Sequence in context: A085971 A175082 A007916 * A109421 A212167 A317090

Adjacent sequences:  A052482 A052483 A052484 * A052486 A052487 A052488

KEYWORD

nonn,easy

AUTHOR

Henry Bottomley, Mar 16 2000

STATUS

approved

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Last modified March 19 15:02 EDT 2019. Contains 321330 sequences. (Running on oeis4.)