Puolivähemäärään

Puolivähemäärään is a Finnish term that translates to "half-semiprime" in English. A semiprime number is a natural number that is the product of two prime numbers. The term "puolivähemäärään" specifically refers to a number that is the product of a prime number and a semiprime number. This means a number can be expressed as p * (q * r), where p, q, and r are prime numbers. It is important to note that the prime numbers p, q, and r do not necessarily have to be distinct.

For example, the number 12 is a puolivähemäärään because it can be expressed as 2 * (2 * 3). Here, 2 and 3 are prime numbers, and (2 * 3) = 6 is a semiprime. Alternatively, 12 can also be expressed as 3 * (2 * 2). Another example is 30, which is 2 * (3 * 5). Here, 2, 3, and 5 are prime numbers, and (3 * 5) = 15 is a semiprime. The concept is a generalization of semiprimes, extending the definition to include numbers formed by three prime factors, where at least two of them are multiplied together to form a semiprime. This type of number is also sometimes referred to as a sphenic number if all three prime factors are distinct, but puolivähemäärään encompasses cases with repeated prime factors.