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A152562 Smallest number m such that sigma(m) has exactly n distinct prime factors. 0
2, 5, 20, 104, 936, 13842, 188424, 3249576, 81239400, 2388809736, 59720243400 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

a(9) = 81239400. Sigma(81239400) = 300690390 = 2*3*5*7*11*13*17*19*31 (9 distinct prime factors).

CROSSREFS

Cf. A000203, A001221.

Sequence in context: A039909 A009551 A006924 * A006867 A170946 A019536

Adjacent sequences:  A152559 A152560 A152561 * A152563 A152564 A152565

KEYWORD

nonn

AUTHOR

Donovan Johnson (donovan.johnson(AT)yahoo.com), Dec 09 2008

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Last modified February 13 22:29 EST 2012. Contains 205567 sequences.