#Sieve

3 posts

Number Theory #0 April 28, 2026 2 min read

Common Formulae — Legendre's Formula & Divisor Convolutions

Legendre’s formula, divisor and multiple convolutions in O(n log n), offline-difference batch processing for H(n)=Σf(d)g(⌊n/d⌋).

#math #number-theory #convolution #divisor #legendre

Number Theory #3 April 28, 2026 5 min read

From Eratosthenes to Möbius Inclusion-Exclusion

Eratosthenes sieve for μ; g/f/h framework; Conclusions 1 and 2 with derivations and tables; GCD table intuition; CF 803F Coprime Subsequences with bottom-up and Möbius approaches.

#math #number-theory #mobius #sieve #inclusion-exclusion

Number Theory #3.1 April 28, 2026 6 min read

Sieve Problems — Coin System DP via Sieve

Greedy optimality for divisibility-chain coin systems, DP over the maximum denomination, and a sieve-style transition by adding one larger coin.

#math #number-theory #sieve #dp #coin-system