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Search: id:A098202
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| A098202 |
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a(n) is the length of the iteration-trajectory when the cototient-function[=A051953] is applied to the n-th primorial number [A002110(n)]. |
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+0
4
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| 3, 5, 8, 12, 18, 20, 31, 32, 41, 43, 61, 65, 80, 77, 95, 125, 131, 125, 157, 173, 140, 192, 195, 221, 213, 212, 261, 269, 277, 300, 296, 321, 336, 329, 358, 367
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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a(n) = A053475(A002110(n)) - Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 22 2004
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EXAMPLE
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n=3: list={30,22,12,8,4,2,1,0}, a(4)=8.
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MATHEMATICA
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g[x_] := x - EulerPhi[x]; f[x_] := Length[ FixedPointList[g, x]] - 1; q[x_] := Product[ Prime[j], {j, x}]; Table[ f[ q[n]], {n, 33}]
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CROSSREFS
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Cf. A051953, A053475, A002110.
Sequence in context: A038088 A018917 A167385 this_sequence A164653 A001973 A020745
Adjacent sequences: A098199 A098200 A098201 this_sequence A098203 A098204 A098205
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Sep 22 2004
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EXTENSIONS
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More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 22 2004
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