Finite Element Methods for Maxwell's Equations
《Finite Element Methods for Maxwell's Equations》 · 第 55 页 · Section 6.1「Brun’s Pure Sieve」
The first successful sieve $\Lambda=(\lambda_d)$, Brun’s pure sieve, was achieved by restricting the Möbius function $\mu(d)$ to numbers $d$ having a limited number of prime divisors.