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A014614
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Numbers that are products of 5 primes (or 5-almost primes, a generalization of semiprimes).
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89
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32, 48, 72, 80, 108, 112, 120, 162, 168, 176, 180, 200, 208, 243, 252, 264, 270, 272, 280, 300, 304, 312, 368, 378, 392, 396, 405, 408, 420, 440, 450, 456, 464, 468, 496, 500, 520, 552, 567, 588, 592, 594, 612, 616, 630, 656, 660, 675, 680, 684, 688, 696
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OFFSET
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1,1
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COMMENTS
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Divisible by exactly 5 prime powers (not including 1).
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LINKS
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T. D. Noe, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Almost Prime
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FORMULA
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Product p_i^e_i with sum e_i = 5.
a(n) ~ 24n log n/(log log n)^4. - Charles R Greathouse IV, Mar 20 2013
a(n) = A078840(5,n). - R. J. Mathar, Jan 30 2019
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MATHEMATICA
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Select[Range[300], Plus @@ Last /@ FactorInteger[ # ] == 5 &] (* Vladimir Joseph Stephan Orlovsky, Apr 23 2008 *)
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PROG
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(PARI) is(n)=bigomega(n)==5 \\ Charles R Greathouse IV, Mar 20 2013
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CROSSREFS
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Cf. A046304, A114453 (number of 5-almost primes <= 10^n).
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), this sequence (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), 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: A090052 A163285 A036329 * A046371 A348824 A175162
Adjacent sequences: A014611 A014612 A014613 * A014615 A014616 A014617
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KEYWORD
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nonn
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AUTHOR
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Eric W. Weisstein
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EXTENSIONS
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More terms from Scott Lindhurst (ScottL(AT)alumni.princeton.edu) and Patrick De Geest, Jun 15 1998
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STATUS
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approved
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