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A107482
Number of prime factors of the smallest n-perfect number.
1
1, 2, 5, 10, 17, 31, 71, 137
OFFSET
1,2
COMMENTS
Multiperfect numbers
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
Sequence in context: A360749 A146268 A038358 * A227363 A372683 A342172
KEYWORD
hard,more,nonn
AUTHOR
Jose Brox (tautocrona(AT)terra.es), May 27 2005
STATUS
approved