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A069278
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17-almost primes (generalization of semiprimes).
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28
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131072, 196608, 294912, 327680, 442368, 458752, 491520, 663552, 688128, 720896, 737280, 819200, 851968, 995328, 1032192, 1081344, 1105920, 1114112, 1146880, 1228800, 1245184, 1277952, 1492992, 1507328, 1548288, 1605632, 1622016
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OFFSET
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1,1
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COMMENTS
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Product of 17 not necessarily distinct primes.
Divisible by exactly 17 prime powers (not including 1).
For n = 1..2628 a(n)=2*A069277(n). - Zak Seidov, Jun 25 2017
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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, Almost Prime.
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FORMULA
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Product p_i^e_i with Sum e_i = 17.
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MATHEMATICA
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Select[Range[2*10^6], PrimeOmega[#]==17&] (* Harvey P. Dale, Sep 28 2016 *)
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PROG
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(PARI) k=17; start=2^k; finish=2000000; 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), A069276 (r = 15), A069277 (r = 16), this sequence (r = 17), A069279 (r = 18), A069280 (r = 19), A069281 (r = 20). - Jason Kimberley, Oct 02 2011
Sequence in context: A069392 A289479 A222529 * A190780 A017698 A010805
Adjacent sequences: A069275 A069276 A069277 * A069279 A069280 A069281
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KEYWORD
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nonn
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AUTHOR
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Rick L. Shepherd, Mar 13 2002
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STATUS
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approved
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