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A155082 Composites k such that the number of prime factors of composite(k) (counted with multiplicity) is composite. 1

%I #12 Feb 11 2019 21:56:26

%S 9,14,24,27,39,42,45,58,60,64,65,74,76,95,99,102,105,114,115,119,122,

%T 141,146,152,168,172,175,176,178,182,187,194,196,201,204,217,231,234,

%U 243,244,249,261,268,273,275,278,279,280,287,291,298,300,301,304,312

%N Composites k such that the number of prime factors of composite(k) (counted with multiplicity) is composite.

%H Muniru A Asiru, <a href="/A155082/b155082.txt">Table of n, a(n) for n = 1..10000</a>

%e 9 (composite) is a term because composite(9) = 16 = 2*2*2*2 (4 prime factors);

%e 14 (composite) is a term because composite(14) = 24 = 2*2*2*3 (4 prime factors);

%e 24 (composite) is a term because composite(24) = 36 = 2*2*3*3 (4 prime factors).

%o (GAP) A:=Filtered([2..500],n->not IsPrime(n));;

%o B:=List(List(A,Factors),Length);;

%o a:=Filtered([1..Length(B)],i->B[i] in A and not IsPrime(i)); # _Muniru A Asiru_, Feb 10 2019

%Y Cf. A000040, A002808, A001222.

%K nonn

%O 1,1

%A _Juri-Stepan Gerasimov_, Jan 20 2009

%E Corrected (45 inserted, 109 removed, 146 replaced with 146 etc.) by _R. J. Mathar_, May 05 2010

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