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Search: id:A081481
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| A081481 |
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Consider the mapping f(a/b) = (a^3 +b^3)/(a^2+b^2). Taking a =1, b = 2 to start with and carrying out this mapping repeatedly on each new (reduced) rational number gives the following sequence 1/2,9/5,427/53,39001680/92569,... Sequence contains the numerator. |
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2
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| 1, 9, 427, 39001680, 59326666963451131888009, 104404652929682490885549887204525469920253354571296599271372511202005
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OFFSET
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1,2
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COMMENT
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The mapping f(a/b) = (a + b)/(a - b). Taking a = 2 b = 1 to start with and carrying out this mapping repeatedly on each new (reduced)rational number gives the periodic sequence 2/1,3/1,2/1,3/1,...
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CROSSREFS
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Cf. A081482.
Sequence in context: A035024 A091061 A024123 this_sequence A160376 A156092 A092813
Adjacent sequences: A081478 A081479 A081480 this_sequence A081482 A081483 A081484
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KEYWORD
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nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 24 2003
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EXTENSIONS
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More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003
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