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Mathematics
Number Theory
1. Foundations of Number Theory
2. Divisibility Theory
3. Prime Numbers and Factorization
4. Greatest Common Divisor and Least Common Multiple
5. Modular Arithmetic and Congruences
6. Classical Theorems in Number Theory
7. Arithmetic Functions
8. Diophantine Equations
9. Quadratic Residues and Reciprocity
10. Prime Number Theory
11. Continued Fractions
12. Elementary Analytic Number Theory
13. Cryptographic Applications
14. Advanced Topics and Connections
Quadratic Residues and Reciprocity
Quadratic Residues
Definition and Basic Properties
Quadratic Non-residues
Examples and Computations
Legendre Symbol
Definition and Notation
Basic Properties
Computational Rules
Multiplicativity
Euler's Criterion
Statement and Proof
Connection to Fermat's Little Theorem
Gauss's Lemma
Statement and Proof
Applications to Quadratic Reciprocity
Quadratic Reciprocity Law
Main Reciprocity Law
First Supplement
Quadratic Character of -1
Second Supplement
Quadratic Character of 2
Proof Strategies
Applications and Examples
Jacobi Symbol
Definition and Properties
Relationship to Legendre Symbol
Computational Advantages
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8. Diophantine Equations
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10. Prime Number Theory