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A107482 Number of prime factors of the smallest n-perfect number. 1
1, 2, 5, 10, 17, 31, 71, 137 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Multiperfect numbers

LINKS

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

Achim Flammenkamp, The Multiply Perfect Numbers Page.

FORMULA

a(n) = A001222(A007539(n))

EXAMPLE

a(4)=10 because the smallest 4-perfect number factorization is 2^5*3^3*5*7 which has 10 prime factors.

CROSSREFS

Cf. A107481

Sequence in context: A173520 A146268 A038358 * A227363 A342172 A262406

Adjacent sequences:  A107479 A107480 A107481 * A107483 A107484 A107485

KEYWORD

hard,more,nonn

AUTHOR

Jose Brox (tautocrona(AT)terra.es), May 27 2005

STATUS

approved

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Last modified June 17 17:46 EDT 2021. Contains 345085 sequences. (Running on oeis4.)