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A102309 Sum[d|n, moebius(d)*C(n/d,2) ]. 3
0, 0, 1, 3, 5, 10, 11, 21, 22, 33, 34, 55, 46, 78, 69, 92, 92, 136, 105, 171, 140, 186, 175, 253, 188, 290, 246, 315, 282, 406, 284, 465, 376, 470, 424, 564, 426, 666, 531, 660, 568, 820, 570, 903, 710, 852, 781, 1081, 760, 1155, 890 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

COMMENTS

Zero followed by the Mobius transform of A000217. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 19 2009]

CROSSREFS

First differences of A100448 (checked up to n=2000).

Second column of triangle A020921.

Sequence in context: A113858 A101130 A191513 * A067230 A075741 A119133

Adjacent sequences:  A102306 A102307 A102308 * A102310 A102311 A102312

KEYWORD

nonn

AUTHOR

Ralf Stephan, Jan 03 2005

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Last modified February 14 13:08 EST 2012. Contains 205623 sequences.