1,4

A minimal number is the smallest number with a given number of divisors, see A007416;

a(n) = A099384(A007416(n)).

a(6) = #{6, 4+2} = 2.

Cf. A099387, A000009, A007416, A005179.

Adjacent sequences: A099385 A099386 A099387 this_sequence A099389 A099390 A099391

Sequence in context: A005855 A096748 A022866 this_sequence A022869 A022865 A089150

nonn

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 14 2004