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 A046312 Numbers that are divisible by exactly 9 primes with multiplicity. 40
 512, 768, 1152, 1280, 1728, 1792, 1920, 2592, 2688, 2816, 2880, 3200, 3328, 3888, 4032, 4224, 4320, 4352, 4480, 4800, 4864, 4992, 5832, 5888, 6048, 6272, 6336, 6480, 6528, 6720, 7040, 7200, 7296, 7424, 7488, 7936, 8000, 8320, 8748, 8832, 9072, 9408 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also called 9-almost primes. Products of exactly 9 primes (not necessarily distinct). - Jonathan Vos Post, Dec 11 2004 LINKS T. D. Noe, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Reference FORMULA Product p_i^e_i with Sum e_i = 9. a(n) ~ 40320n log n / (log log n)^8. - Charles R Greathouse IV, May 06 2013 MATHEMATICA Select[Range, Plus @@ Last /@ FactorInteger[ # ] == 9 &] (* Vladimir Joseph Stephan Orlovsky, Apr 23 2008 *) PROG (PARI) is(n)=bigomega(n)==9 \\ Charles R Greathouse IV, Mar 21 2013 CROSSREFS Cf. A046311, A120050 (number of 9-almost primes <= 10^n). Cf. A101637, A101638, A101605, A101606. 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 Sequence in context: A202461 A046311 A036333 * A045033 A066648 A043423 Adjacent sequences:  A046309 A046310 A046311 * A046313 A046314 A046315 KEYWORD nonn AUTHOR Patrick De Geest, Jun 15 1998 STATUS approved

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Last modified November 14 15:15 EST 2019. Contains 329126 sequences. (Running on oeis4.)