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Search: id:A049117
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| A049117 |
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Smallest number which when Euler phi function is repeatedly applied have not reached a power of 2 in n steps. |
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+0
3
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| 3, 7, 19, 47, 163, 487, 1307, 2879, 19683, 39367, 177147, 531441, 1594323, 4782969, 14348907, 43046721, 86093443, 258280327, 688747547
(list; graph; listen)
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OFFSET
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0,1
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EXAMPLE
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The corresponding iterated phi-sequences are: {3,2,1}, {7,6,2,1}, {19,18,6,2,1}, {47,46,22,10,4,2,1}, {163,162,54,18,6,2,1}, {487,486,162,54,18,6,2,1}, ...
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MATHEMATICA
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a[n_] := Module[{i = 1}, While[IntegerQ[Log[2, Nest[EulerPhi, i, n]]], i++ ]; i]; - Sam Handler (sam_5_5_5_0(AT)yahoo.com), Sep 04 2006
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CROSSREFS
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Cf. A000010.
Sequence in context: A110014 A026581 A001372 this_sequence A073063 A007288 A061646
Adjacent sequences: A049114 A049115 A049116 this_sequence A049118 A049119 A049120
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KEYWORD
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nonn,more
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu)
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EXTENSIONS
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More terms from Jud McCranie (j.mccranie(AT)comcast.net), Jan 14 2000
More terms from Sam Handler (sam_5_5_5_0(AT)yahoo.com), Sep 04 2006
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