Concepts4
∑MathIntermediate
Multiplicative Functions
A multiplicative function is an arithmetic function f with f(mn) = f(m)f(n) whenever gcd(m, n) = 1.
#multiplicative function#dirichlet convolution#mobius function+12
∑MathIntermediate
Euler's Totient Function
Euler's Totient Function φ(n) counts how many integers from 1 to n are coprime with n.
#euler totient#phi function#coprime count+12
∑MathIntermediate
Linear Sieve
The linear sieve builds all primes up to n in O(n) time by ensuring each composite is marked exactly once by its smallest prime factor (SPF).
#linear sieve#smallest prime factor#spf+12
∑MathIntermediate
Sieve of Eratosthenes
The Sieve of Eratosthenes marks multiples of each prime to find all primes up to n in O(n log log n) time.
#sieve of eratosthenes#segmented sieve#linear sieve+11