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Search: id:A077095
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| A077095 |
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Starting iteration of Phi[]*(Sigma[]-Phi[]) function at these initial values leads to the fixed point 24. |
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+0
1
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| 24, 42, 69, 74, 75, 82, 86, 94, 115, 125, 133, 155, 185, 187, 203, 289, 299, 323, 341, 361, 377, 437, 1681
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Probably this sequence is finite, with 23 terms of which the last is 1681.
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EXAMPLE
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n=1641: FixedPointList={1681,82,42,24},end=24.
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MATHEMATICA
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f[x_] := EulerPhi[DivisorSigma[1, x]-EulerPhi[x]] Do[s=NestList[f, n, 100]; s1=Part[s, 99]; s2=Part[s, 100]; If[Equal[s1, s2]&&Equal[s1, 4], Print[{n, s1}]], {n, 1, 1000000}]
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CROSSREFS
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Cf. A077090-A077100.
Sequence in context: A162886 A063702 A074975 this_sequence A111948 A039411 A043234
Adjacent sequences: A077092 A077093 A077094 this_sequence A077096 A077097 A077098
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KEYWORD
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nonn,fini,full
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Oct 31 2002
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