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Search: id:A100613
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| A100613 |
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Number of elements in the set {(x,y): 1<=x,y<=n, gcd(x,y) > 1}. |
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+0
4
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| 0, 1, 2, 5, 6, 13, 14, 21, 26, 37, 38, 53, 54, 69, 82, 97, 98, 121, 122, 145, 162, 185, 186, 217, 226, 253, 270, 301, 302, 345, 346, 377, 402, 437, 458, 505, 506, 545, 574, 621, 622, 681, 682, 729, 770, 817, 818, 881, 894, 953, 990, 1045, 1046, 1117, 1146, 1209
(list; graph; listen)
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OFFSET
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1,3
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MATHEMATICA
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f[n_] := Table[ #^2 &[m], {m, 1, n + 1}] - FoldList[Plus, 1, 2 Array[EulerPhi, n, 2]] - Gregg Whisler (gkwhisler(AT)msn.com), Jun 25 2008
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CROSSREFS
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Cf. A018805.
Cf. A018805.
Sequence in context: A082552 A057683 A069480 this_sequence A070911 A113240 A098376
Adjacent sequences: A100610 A100611 A100612 this_sequence A100614 A100615 A100616
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KEYWORD
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nonn
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AUTHOR
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Douglas Stones (dssto1(AT)student.monash.edu.au), Dec 02 2004
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