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Search: id:A093911
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| A093911 |
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Group the natural numbers so that the n-th group has at least n members and every group product is a multiple of that of the previous group. a(n) is the first member of the n-th group. |
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+0
4
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| 1, 2, 4, 7, 11, 17, 27, 47, 87, 167, 327, 635, 1263, 2519, 5007, 10007, 19947, 39875, 79739, 159399, 318779, 637503, 1274999, 2549979, 5099903, 10199787, 20399535, 40799063, 81598083, 163196135, 326392259, 652784499, 1305568943, 2611137839
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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The first 5 groups are (1), (2,3), (4,5,6), (7,8,9,10),
(11,12,13,14,15,16). The 5th group ends with 16 because
11*12*13*14*15*16 is divisible by 7*8*9*10, but 11*12*13*14*15 is not.
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CROSSREFS
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Cf. A090905, A093910, A093912, A093913.
Sequence in context: A023430 A023429 A023428 this_sequence A152398 A023427 A129929
Adjacent sequences: A093908 A093909 A093910 this_sequence A093912 A093913 A093914
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KEYWORD
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nonn,easy,less
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 24 2004
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EXTENSIONS
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Edited and extended by David Wasserman (dwasserm(AT)earthlink.net), Mar 27 2006
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