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A212490 Least number m > 1 such that A000203(x)*x = m has exactly n solutions. 3
6, 336, 333312, 5418319872, 1584858562560 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

6 = 6.

336 = 6*28*2.

333312 = 6*28*496*2*2.

5418319872 = 6*28*496*8128*2*2*2.

REFERENCES

R. K. Guy, Unsolved Problems in Theory of Numbers, Springer-Verlag, Third Edition, 2004, B11.

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

For n=3, 333312 has exactly 3 solutions: sigma(434)*434 = 333312, sigma(372)*372 = 333312, and sigma(336)*336 = 333312; therefore a(3) = 333312.

CROSSREFS

Cf. A212489, A212327, A212373.

Sequence in context: A210769 A003031 A144849 * A047941 A229501 A289738

Adjacent sequences:  A212487 A212488 A212489 * A212491 A212492 A212493

KEYWORD

nonn,more

AUTHOR

Naohiro Nomoto, May 18 2012

EXTENSIONS

a(5) from Donovan Johnson, May 20 2012

STATUS

approved

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Last modified March 28 07:59 EDT 2020. Contains 333079 sequences. (Running on oeis4.)