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Search: id:A091857
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| A091857 |
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Beginning with 1, (a(2n-1),a(2n)) = 1, (a(2n),a(2n+1))>1; a(n) is smallest value not yet used that makes this true. |
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+0
2
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| 1, 2, 4, 3, 6, 5, 10, 7, 14, 9, 12, 11, 22, 13, 26, 15, 18, 17, 34, 19, 38, 21, 24, 23, 46, 25, 20, 27, 30, 29, 58, 31, 62, 33, 36, 35, 28, 37, 74, 39, 42, 41, 82, 43, 86, 45, 40, 47, 94, 49, 56, 51, 54, 53, 106, 55, 50, 57, 60, 59, 118, 61, 122, 63, 48, 65, 52, 67, 134, 69, 66
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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It seems that for n>1, a(2n-1) is always even, which forces a(2n) to be odd. Together, these prevent any further powers of 2 from appearing in the sequence. In fact, it appears that a(2n+1) is always either less than a(2n) or equal to a(2n) + the least prime factor of a(2n); and very rarely is a(2n) anything other than the smallest odd number not yet used (the first instance for n>1 is a(96) = 97 instead of 95). - Frank Adams-Watters (FrankTAW(AT)Netscape.net), Sep 01 2006
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CROSSREFS
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Cf. A091856.
Sequence in context: A082560 A127202 A034701 this_sequence A132340 A132666 A116533
Adjacent sequences: A091854 A091855 A091856 this_sequence A091858 A091859 A091860
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KEYWORD
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easy,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 13 2004
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EXTENSIONS
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More terms from Frank Adams-Watters (FrankTAW(AT)Netscape.net), Sep 01 2006
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