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Search: id:A069277
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| A069277 |
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16-almost primes (generalization of semiprimes). |
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+0
9
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| 65536, 98304, 147456, 163840, 221184, 229376, 245760, 331776, 344064, 360448, 368640, 409600, 425984, 497664, 516096, 540672, 552960, 557056, 573440, 614400, 622592, 638976, 746496, 753664, 774144, 802816, 811008, 829440, 835584, 860160
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Divisible by exactly 16 primes (counted with multiplicity).
Any 16-almost prime can be represented in several ways as a product of two 8-almost primes A046310; in several ways as a product of four 4-almost primes A014613; and in several ways as a product of eight semiprimes A001358. - Jonathan Vos Post (jvospost3(AT)gmail.com), Dec 12 2004
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LINKS
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D. W. Wilson, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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FORMULA
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Product p_i^e_i with Sum e_i = 16.
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MATHEMATICA
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Select[Range[300000], Plus @@ Last /@ FactorInteger[ # ] == 16 &] - Vladimir Orlovsky, Apr 23 2008
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PROGRAM
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(PARI) k=16; start=2^k; finish=1000000; v=[] for(n=start, finish, if(bigomega(n)==k, v=concat(v, n))); v
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CROSSREFS
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Cf. A001358 (semiprimes), A069276 (15-almost primes), A069278 (17-almost primes) - A069281 (20-almost primes).
Cf. A014610, A014613, A001358, A101637, A101638, A101605, A101606.
Sequence in context: A011566 A022532 A069391 this_sequence A016784 A016808 A016904
Adjacent sequences: A069274 A069275 A069276 this_sequence A069278 A069279 A069280
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KEYWORD
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nonn
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AUTHOR
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Rick L. Shepherd (rshepherd2(AT)hotmail.com), Mar 13 2002
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