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A007668 phi(n) divides sigma(n) and sigma(n)/n > sigma(m)/m for all m < n. 0
1, 2, 6, 12, 840, 332640 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..6.

CROSSREFS

Cf. A020492, A004394.

Sequence in context: A298410 A074180 A126293 * A089415 A282974 A181063

Adjacent sequences:  A007665 A007666 A007667 * A007669 A007670 A007671

KEYWORD

nonn

AUTHOR

Walter Nissen

STATUS

approved

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Last modified September 20 05:51 EDT 2019. Contains 327212 sequences. (Running on oeis4.)