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# Least prime factor of n

(Redirected from Lpf(n))

The least prime factor of an integer ${\displaystyle n}$ is the smallest prime number that divides the number. For example, the least prime factor of 945 is 3. The least prime factor of all even numbers is 2. A prime number is its own least prime factor (as well as its own greatest prime factor).
Smallest prime dividing ${\displaystyle \scriptstyle n,\,n\,\geq \,2,\,}$ gives the sequence (Cf. A020639 Lpf(n): least prime dividing n, with ${\displaystyle \scriptstyle a(1)\,=\,1\,}$.)