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Search: id:A083244
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| A083244 |
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n is in the sequence iff number of numbers unrelated to n is larger than that of related ones[=divisors and coprimes] to n: A045763[n]>A073757[n] or A045763[n]>n/2 or A073757[n]<n/2. |
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+0
4
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| 42, 54, 60, 66, 70, 72, 78, 84, 90, 96, 98, 100, 102, 108, 110, 114, 120, 126, 130, 132, 138, 140, 144, 150, 154, 156, 160, 162, 168, 170, 174, 180, 182, 186, 190, 192, 196, 198, 200, 204, 210, 216, 220, 222, 224, 228, 230, 234, 238, 240, 242, 246, 250, 252
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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n-d[n]-phi[n]+1>n/2
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EXAMPLE
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n=42 is here because d=8 divisors, r=12 coprimes
and u=23 unrelated belong to it: u=23>19=8+12-1=d+r-1.
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MATHEMATICA
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Do[r=EulerPhi[n]; d=DivisorSigma[0, n]; u=n-d-r+1; If[Greater[u, n/2], Print[n, {d, r, u}]], {n, 1, 100}]
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CROSSREFS
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Cf. A000005, A000010, A045763, A073757, A020488, A083243, A083245.
Adjacent sequences: A083241 A083242 A083243 this_sequence A083245 A083246 A083247
Sequence in context: A105346 A108119 A116262 this_sequence A125009 A008886 A029695
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)amna1.sote.hu), May 07 2003
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