期刊名称：International Journal of Computer and Information Technology
印刷版ISSN：2279-0764
出版年度：2017
卷号：6
期号：1
页码：49-54
出版社：International Journal of Computer and Information Technology
摘要：In this paper we give a new semiprimality test and we
construct a new formula for
(2) ( ) N
, the function that counts the
number of semiprimes not exceeding a given number
N
. We also
present new formulas to identify the
th
n
semiprime and the next
semiprime to a given number. The new formulas are based on the
knowledge of the primes less than or equal to the cube roots of
3
3
1 2 : , .... N
N P P P N
.
关键词：prime; semiprime;
th
n
semiprime; next
semiprime
