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%I #29 Oct 26 2023 18:38:21
%S 16,24,32,36,40,48,54,56,60,64,72,80,81,84,88,90,96,100,104,108,112,
%T 120,126,128,132,135,136,140,144,150,152,156,160,162,168,176,180,184,
%U 189,192,196,198,200,204,208,210,216,220,224,225,228,232,234,240,243
%N Numbers that are divisible by at least 4 primes (counted with multiplicity).
%C Complement of A037144: A001222(a(n)) > 3; A117358(a(n)) > 1. - _Reinhard Zumkeller_, Mar 10 2006
%C Also numbers such that no permutation of all proper divisors exists with coprime adjacent elements: A178254(a(n)) = 0. - _Reinhard Zumkeller_, May 24 2010
%C Also, numbers that can be written as a product of at least two composites, i.e., admit a nontrivial factorization into composites. - _Felix Fröhlich_, Dec 22 2018
%H T. D. Noe, <a href="/A033987/b033987.txt">Table of n, a(n) for n=1..1000</a>
%F Product p_i^e_i with Sum e_i >= 4.
%F A001055(a(n)) > A033273(a(n)). - _Juri-Stepan Gerasimov_, Nov 09 2009
%p with(numtheory): A033987:=n->`if`(bigomega(n)>3, n, NULL): seq(A033987(n), n=1..300); # _Wesley Ivan Hurt_, May 26 2015
%t Select[Range[300],PrimeOmega[#]>3&] (* _Harvey P. Dale_, Mar 20 2016 *)
%o (PARI) is(n)=bigomega(n)>3 \\ _Charles R Greathouse IV_, May 26 2015
%Y Subsequence of A033942; A178212 is a subsequence.
%Y Cf. A014613, A001055, A033273.
%K nonn,easy
%O 1,1
%A _N. J. A. Sloane_
%E More terms from _Patrick De Geest_, Jun 15 1998
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