Number Theory #3: 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.
Inclusion-Exclusion
Index
All notes
Combinatorics D1: Diophantine Equations
Stars and bars, bounded Diophantine equations via inclusion-exclusion, prefix-sum DP, D&C NTT, equal-cap formula, and a full worked example on CF 2127F.
Combinatorics #1.2: Inclusion-Exclusion, Bounded Diophantine Equations, and Derangements
Inclusion-exclusion in set and operator form, equal-count subproblems, bounded Diophantine counting, derangements, Stirling numbers, and selected contest problems.