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A033847
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Numbers n whose prime factors are 2 and 7.
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10
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14, 28, 56, 98, 112, 196, 224, 392, 448, 686, 784, 896, 1372, 1568, 1792, 2744, 3136, 3584, 4802, 5488, 6272, 7168, 9604, 10976, 12544, 14336, 19208, 21952, 25088, 28672, 33614, 38416, 43904, 50176, 57344, 67228, 76832, 87808, 100352, 114688
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| n such that phi(n)=(3/7)*n - Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 19 2002
A143201(a(n)) = 6; subsequence of A143204. [Reinhard Zumkeller, Sep 13 2011]
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LINKS
| Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
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PROG
| (Haskell)
import Data.Set (singleton, deleteFindMin, insert)
a033847 n = a033847_list !! (n-1)
a033847_list = f (singleton (2*7)) where
f s = m : f (insert (2*m) $ insert (7*m) s') where
(m, s') = deleteFindMin s
-- Reinhard Zumkeller, Sep 13 2011
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CROSSREFS
| Cf. A033845, A033846, A033848, A033849, A033850, A033851.
Sequence in context: A044839 A033011 A077265 * A067295 A019552 A174070
Adjacent sequences: A033844 A033845 A033846 * A033848 A033849 A033850
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KEYWORD
| nonn
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AUTHOR
| Jeff Burch (gburch(AT)erols.com)
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EXTENSIONS
| Offset fixed by Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 13 2011
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