from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A natural number that is the product of two prime numbers.
The last chapters of this volume provide the theory of semiprime Noetherian semiperfect and semidistributive rings.
A133850 Number of partitions of n into two primes and a semiprime. at AT&T Research Labs’ Online Encyclopedia of Integer Sequences.
What was the number? a1: It is the difference between two squares a2: It is not the sum of two cubes b1: It is an even number b2: It does not have exactly two prime factors (it is semiprime; ie, of the form a*b where a and b are both prime) c1: It is the sum of two squares c2: It is both a square and a cube d1: It has exactly three prime factors d2: It is prime e1: It is the sum of a square and a cube e2: It is the sum of three squares