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A064016
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Sum_{ k <= 10^n } cototient(k).
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0
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0, 23, 2006, 196308, 19607514, 1960399246, 196036947608, 19603648572758, 1960364533634092, 196036449326991586, 19603644912113783634, 1960364490766613788860, 196036449073440195974090
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Conjecture: It would appear that the sum from 1 to n approaches the limit 0.1960364*n^2 = (1/2 - 3/Pi^2)*n^2.
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MATHEMATICA
| s = 0; k = 1; Do[ While[ k <= 10^n, s = s + k - EulerPhi[ k ]; k++ ]; Print[ s ], {n, 0, 8} ]
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CROSSREFS
| Cf. A051953, A002088, A063986.
Sequence in context: A183480 A002439 A132395 * A138735 A132937 A068655
Adjacent sequences: A064013 A064014 A064015 * A064017 A064018 A064019
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KEYWORD
| nonn,changed
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 07 2001
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EXTENSIONS
| a(9) from Jud McCranie, Jun 25, 2005.
a(10)-a(11) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 06 2010
a(12) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 07 2012
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