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A093599 Composite numbers having an odd number of prime factors, all of which are distinct. 2

%I #30 Dec 23 2020 17:35:53

%S 30,42,66,70,78,102,105,110,114,130,138,154,165,170,174,182,186,190,

%T 195,222,230,231,238,246,255,258,266,273,282,285,286,290,310,318,322,

%U 345,354,357,366,370,374,385,399,402,406,410,418,426,429,430,434,435

%N Composite numbers having an odd number of prime factors, all of which are distinct.

%C First differs from A007304 at 2*3*5*7*11 = 2310, which is a(360) and thus beyond the tabulated range.

%C Subsequence of A030059. - _Bill McEachen_, Nov 06 2020

%H Carl R. White, <a href="/A093599/b093599.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeSums.html">Prime Sums</a>

%H Wikipedia, <a href="http://en.wikipedia.org/wiki/M%F6bius_function">Moebius function</a>

%t Select[Range[435], MoebiusMu[ # ] == -1 && Not[PrimeQ[ # ]] &] (* _Alonso del Arte_, Jan 24 2005 *)

%o (PARI) is(n)=my(f=factor(n)[,2]); #f>2 && #f%2==1 && vecmax(f)==1 \\ _Charles R Greathouse IV_, Oct 19 2015

%Y Cf. A007304, A030059.

%K nonn

%O 1,1

%A _Eric W. Weisstein_, Apr 03 2004

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Last modified April 19 21:09 EDT 2024. Contains 371798 sequences. (Running on oeis4.)