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%I #33 Oct 24 2020 14:13:55
%S 512,768,1152,1280,1728,1792,1920,2592,2688,2816,2880,3200,3328,3888,
%T 4032,4224,4320,4352,4480,4800,4864,4992,5832,5888,6048,6272,6336,
%U 6480,6528,6720,7040,7200,7296,7424,7488,7936,8000,8320,8748,8832,9072,9408
%N Numbers that are divisible by exactly 9 primes with multiplicity.
%C Also called 9-almost primes. Products of exactly 9 primes (not necessarily distinct). - _Jonathan Vos Post_, Dec 11 2004
%H T. D. Noe, <a href="/A046312/b046312.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AlmostPrime.html">Reference</a>
%F Product p_i^e_i with Sum e_i = 9.
%F a(n) ~ 40320n log n / (log log n)^8. - _Charles R Greathouse IV_, May 06 2013
%t Select[Range[2200], Plus @@ Last /@ FactorInteger[ # ] == 9 &] (* _Vladimir Joseph Stephan Orlovsky_, Apr 23 2008 *)
%t Select[Range[10000],PrimeOmega[#]==9&] (* _Harvey P. Dale_, Oct 24 2020 *)
%o (PARI) is(n)=bigomega(n)==9 \\ _Charles R Greathouse IV_, Mar 21 2013
%Y Cf. A046311, A120050 (number of 9-almost primes <= 10^n).
%Y Cf. A101637, A101638, A101605, A101606.
%Y Sequences listing r-almost primes, that is, the n such that A001222(n) = r: A000040 (r = 1), A001358 (r = 2), A014612 (r = 3), A014613 (r = 4), A014614 (r = 5), A046306 (r = 6), A046308 (r = 7), A046310 (r = 8), this sequence (r = 9), A046314 (r = 10), A069272 (r = 11), A069273 (r = 12), A069274 (r = 13), A069275 (r = 14), A069276 (r = 15), A069277 (r = 16), A069278 (r = 17), A069279 (r = 18), A069280 (r = 19), A069281 (r = 20). - _Jason Kimberley_, Oct 02 2011
%K nonn
%O 1,1
%A _Patrick De Geest_, Jun 15 1998
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