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A069276
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15-almost primes (generalization of semiprimes).
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29
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32768, 49152, 73728, 81920, 110592, 114688, 122880, 165888, 172032, 180224, 184320, 204800, 212992, 248832, 258048, 270336, 276480, 278528, 286720, 307200, 311296, 319488, 373248, 376832, 387072, 401408, 405504, 414720, 417792, 430080
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OFFSET
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1,1
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COMMENTS
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Product of 15 not necessarily distinct primes.
Divisible by exactly 15 prime powers (not including 1).
Any 15-almost prime can be represented in several ways as a product of three 5-almost primes A014614, and in several ways as a product of five 3-almost primes A014612. - Jonathan Vos Post, Dec 11 2004
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LINKS
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FORMULA
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Product p_i^e_i with Sum e_i = 15.
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MATHEMATICA
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Select[Range[450000], PrimeOmega[#]==15&] (* Harvey P. Dale, Aug 14 2019 *)
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PROG
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(PARI) k=15; start=2^k; finish=500000; v=[] for(n=start, finish, if(bigomega(n)==k, v=concat(v, n))); v
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CROSSREFS
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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), A046312 (r = 9), A046314 (r = 10), A069272 (r = 11), A069273 (r = 12), A069274 (r = 13), A069275 (r = 14), this sequence (r = 15), A069277 (r = 16), A069278 (r = 17), A069279 (r = 18), A069280 (r = 19), A069281 (r = 20). - Jason Kimberley, Oct 02 2011
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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