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A106543 Composite numbers that are not perfect powers. 8
6, 10, 12, 14, 15, 18, 20, 21, 22, 24, 26, 28, 30, 33, 34, 35, 38, 39, 40, 42, 44, 45, 46, 48, 50, 51, 52, 54, 55, 56, 57, 58, 60, 62, 63, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 82, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 102, 104, 105, 106 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..66.

FORMULA

a(n) = n + O(n/log n). - Charles R Greathouse IV, Oct 03 2011

MATHEMATICA

perfPQ[n_]:=GCD@@FactorInteger[n][[All, 2]]>1; Select[Range[110], CompositeQ[ #] && !perfPQ[#]&] (* Harvey P. Dale, Oct 10 2017 *)

PROG

(PARI) lista(nn)=forcomposite(i=1, nn, if (! ispower(i), print1(i, ", ")); ); \\ Michel Marcus, Jun 27 2013

(PARI) is(n)=!isprime(n) && !ispower(n) && n>1 \\ Charles R Greathouse IV, Oct 19 2015

(CASE)

def A106543_list(n) : return [k for k in (2..n) if not k.is_prime() and not k.is_perfect_power()]

A106543_list(106) # Terry D. Grant, Jul 17 2016

CROSSREFS

Intersection of A002808 and A007916.

Cf. A105642, A089229.

Sequence in context: A335080 A323304 A325411 * A324455 A327476 A007774

Adjacent sequences:  A106540 A106541 A106542 * A106544 A106545 A106546

KEYWORD

easy,nonn

AUTHOR

Alexandre Wajnberg, May 08 2005

STATUS

approved

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Last modified June 12 10:29 EDT 2021. Contains 344946 sequences. (Running on oeis4.)