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Search: id:A070016
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| A070016 |
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Least m such that Chowla-function value of m [A048050(m)] equals n or 0 if no such number exists. |
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+0
2
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| 0, 4, 9, 0, 6, 8, 10, 15, 14, 21, 121, 27, 22, 16, 12, 39, 289, 65, 34, 18, 20, 57, 529, 95, 46, 69, 28, 115, 841, 32, 58, 45, 62, 93, 24, 155, 1369, 217, 44, 63, 30, 50, 82, 123, 52, 129, 2209, 75, 40, 141, 0, 235, 42, 36, 106, 99, 68, 265, 3481, 371, 118, 64, 56, 117
(list; graph; listen)
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OFFSET
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1,2
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COMMENT
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Remark that A070016(n)=A070015(n+1) in accordance with A048995(k)+1=A005114(k).
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FORMULA
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a(n)=Min{x; A048050(x)=n} or a(n)=0 if n is from A048995.
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EXAMPLE
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n=127: a(n)=16129, divisors={1,127,16129}, 127=sigma[n]-n-1=127 and 16129 is the smallest.
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MATHEMATICA
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f1[x_] := DivisorSigma[1, x]-x-1; t=Table[0, {128}]; Do[b=f1[n]; If[b<129&&t[[b]]==0, t[[b]]=n], {n, 1, 1000000}]; t
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CROSSREFS
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Cf. A000203, A001065, A048050, A051444, A007369, A070016, A005114, A048995.
Sequence in context: A021208 A021675 A093872 this_sequence A020802 A085675 A070439
Adjacent sequences: A070013 A070014 A070015 this_sequence A070017 A070018 A070019
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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), Apr 12 2002
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