A086568 - OEIS

A086568

Smallest number having as many distinct prime factors as n has prime factors, when counted with multiplicity.

1, 2, 2, 6, 2, 6, 2, 30, 6, 6, 2, 30, 2, 6, 6, 210, 2, 30, 2, 30, 6, 6, 2, 210, 6, 6, 30, 30, 2, 30, 2, 2310, 6, 6, 6, 210, 2, 6, 6, 210, 2, 30, 2, 30, 30, 6, 2, 2310, 6, 30, 6, 30, 2, 210, 6, 210, 6, 6, 2, 210, 2, 6, 30, 30030, 6, 30, 2, 30, 6, 30, 2, 2310, 2, 6, 30, 30, 6, 30, 2

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OFFSET

1,2

COMMENTS

a(n) = n if and only if n = A002110(m) for some m. That is, primorials give the fixed points of this sequence.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..2310

Index entries for sequences computed from exponents in factorization of n

FORMULA

a(n) = prime(bigomega(n))# = A002110(A001222(n)).

For all n >= 1, A001221(a(n)) = A001222(a(n)) = A001222(n).

MATHEMATICA