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A046306
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Numbers that are divisible by exactly 6 prime powers (not including 1).
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52
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64, 96, 144, 160, 216, 224, 240, 324, 336, 352, 360, 400, 416, 486, 504, 528, 540, 544, 560, 600, 608, 624, 729, 736, 756, 784, 792, 810, 816, 840, 880, 900, 912, 928, 936, 992, 1000, 1040, 1104, 1134, 1176, 1184, 1188, 1215, 1224, 1232, 1260, 1312, 1320
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Also called 6-almost primes. Products of exactly 6 primes (not necessarily distinct). Any 6-almost prime can be represented in several ways as a product of two 3-almost primes A014612 and in several ways as a product of three semiprimes A001358. - Jonathan Vos Post (jvospost3(AT)gmail.com), Dec 11 2004
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LINKS
| T. D. Noe, Table of n, a(n) for n=1..10000
Eric Weisstein's World of Mathematics, Reference
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FORMULA
| Product p_i^e_i with Sum e_i = 6.
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MATHEMATICA
| Select[Range[500], Plus @@ Last /@ FactorInteger[ # ] == 6 &] - Vladimir Orlovsky, Apr 23 2008
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CROSSREFS
| Cf. A046305, A120047 (number of 6-almost primes <= 10^n).
Cf. A101605, A101606.
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), this sequence (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: A046305 A114828 A036330 * A175163 A104022 A061099
Adjacent sequences: A046303 A046304 A046305 * A046307 A046308 A046309
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KEYWORD
| nonn
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AUTHOR
| Patrick De Geest (pdg(AT)worldofnumbers.com), Jun 15 1998.
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