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A069274
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13-almost primes (generalization of semiprimes).
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26
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8192, 12288, 18432, 20480, 27648, 28672, 30720, 41472, 43008, 45056, 46080, 51200, 53248, 62208, 64512, 67584, 69120, 69632, 71680, 76800, 77824, 79872, 93312, 94208, 96768, 100352, 101376, 103680, 104448, 107520, 112640, 115200
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Product of 13 not necessarily distinct primes.
Divisible by exactly 13 prime powers (not including 1).
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LINKS
| 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
| Product p_i^e_i with Sum e_i = 13.
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MATHEMATICA
| Select[Range[30000], Plus @@ Last /@ FactorInteger[ # ] == 13 &] - Vladimir Orlovsky, Apr 23 2008
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PROG
| (PARI) k=13; start=2^k; finish=130000; v=[] for(n=start, finish, if(bigomega(n)==k, v=concat(v, n))); v
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CROSSREFS
| 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), this sequence (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: A022195 A069388 A069414 * A195661 A017690 A010801
Adjacent sequences: A069271 A069272 A069273 * A069275 A069276 A069277
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KEYWORD
| nonn
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AUTHOR
| Rick L. Shepherd (rshepherd2(AT)hotmail.com), Mar 13 2002
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