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Search: id:A091369
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A091369 a(n) = sum_{i=1..n} eulerphi(i)*ceil(n/i). +0
1
1, 3, 7, 12, 20, 27, 39, 50, 64, 77, 97, 112, 136, 155, 177, 200, 232, 255, 291, 318, 350, 381, 425, 456, 500, 537, 581, 620, 676, 713, 773, 820, 872, 921, 979, 1026, 1098, 1153, 1215, 1270, 1350, 1403, 1487, 1550, 1618, 1685, 1777, 1840, 1930, 1999, 2081, 2156 (list; graph; listen)
OFFSET

1,2

MATHEMATICA

A091369[n_] := Sum[EulerPhi[i]*Ceiling[n/i], {i, n}] (from Robert G. Wilson v Mar 02 2004)

CROSSREFS

Cf. A000217.

Sequence in context: A039677 A011899 A002498 this_sequence A036698 A132273 A130050

Adjacent sequences: A091366 A091367 A091368 this_sequence A091370 A091371 A091372

KEYWORD

nonn

AUTHOR

Jon Perry (perry(AT)globalnet.co.uk), Mar 01 2004

EXTENSIONS

More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 02 2004

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Last modified September 6 16:04 EDT 2008. Contains 143483 sequences.


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