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A219221 Numbers n such that sigma(n)*tau(n) is a perfect number. 0
2, 13, 3554677, 7339129, 8125441, 910156807, 2080358881, 14914915687 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(9) > A002182(111). - Donovan Johnson, Aug 22 2013

LINKS

Table of n, a(n) for n=1..8.

FORMULA

Numbers n such that sigma(n)*tau(n) is a perfect number.

CROSSREFS

Cf. A000005, A000203, A000396.

Sequence in context: A262299 A135970 A027738 * A249510 A324219 A196815

Adjacent sequences:  A219218 A219219 A219220 * A219222 A219223 A219224

KEYWORD

nonn

AUTHOR

Zdenek Cervenka, Nov 15 2012

EXTENSIONS

a(6)-a(7) from Donovan Johnson, Nov 15 2012

a(8) from Donovan Johnson, Aug 22 2013

STATUS

approved

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Last modified November 22 10:59 EST 2019. Contains 329389 sequences. (Running on oeis4.)