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A number *N *is considered special if for *N = k/d(k)*, where *d(k)* is the number of divisors of *k*, there are two distinct integer solutions. Similarly, a number *N *is considered very special if both solutions of *N = k/d(k) *are special numbers as well.

What numbers in the range 1 ≤ x ≤ 25 are very special numbers? (Put your answers in the form *N _{1},N_{2},...N_{n}*)

*N _{1},N_{2},...N_{n}*)