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Search: id:A098221
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| A098221 |
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a[n] is the smallest number x such that Floor[sigma[sigma[x]]/x]=n or A098219[x] quotient equals n. |
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+0
2
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| 1, 2, 8, 6, 40, 30, 24, 60, 120, 480, 540, 1560, 2520, 10920, 27720, 30240, 191520, 524160, 360360
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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a[n]=Min{x;Floor[A051027[x]/x]=n}
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EXAMPLE
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n=10:a[10]=480 because Floor[sigma[sigma[480]]/480]=Floor[sigma[1512]/480]=
Floor[4800/480]=4800/480=n=10.
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MATHEMATICA
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t=Table[0, {100}]; Do[s=g[n]; If[s<101&&t[[s]]==0, t[[s]]=n], {n, 1, 1000000}]; t
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CROSSREFS
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Cf. A000203, A051027, A008333, A098219-A098222.
Adjacent sequences: A098218 A098219 A098220 this_sequence A098222 A098223 A098224
Sequence in context: A069895 A085590 A079538 this_sequence A009214 A021781 A130820
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KEYWORD
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more,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Oct 25 2004
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