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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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3
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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; refs; listen; history; internal format)
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OFFSET
| 1,1
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FORMULA
| a(n) = A053475(A002110(n)) - Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 22 2004
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EXAMPLE
| n=3: list={30,22,12,8,4,2,1,0}, a(4)=8.
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MATHEMATICA
| 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
| Cf. A051953, A053475, A002110.
Sequence in context: A038088 A018917 A167385 * A164653 A001973 A020745
Adjacent sequences: A098199 A098200 A098201 * A098203 A098204 A098205
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KEYWORD
| nonn
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AUTHOR
| Labos E. (labos(AT)ana.sote.hu), Sep 22 2004
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EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 22 2004
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