Book:George E. Andrews/Number Theory
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George E. Andrews: Number Theory
Published $\text {1971}$, Dover Publications, Inc.
- ISBN 0-486-68252-8
Subject Matter
Contents
- Preface
- Part I: Multiplicativity - Divisibility
- Chapter 1: Basis Representation
- Chapter 2: The Fundamental Theorem of Arithmetic
- Chapter 3: Combinatorial and Computational Number Theory
- Chapter 4: Fundamentals of Congruences
- Chapter 5: Solving Congruences
- Chapter 6: Arithmetic Functions
- Chapter 7: Primitive Roots
- Chapter 8: Prime Numbers
- Part II: Quadratic Congruences
- Chapter 9: Quadratic Residues
- Chapter 10: Distribution of Quadratic Residues
- Part III: Additivity
- Chapter 11: Sums of Squares
- Chapter 12: Elementary Partition Theory
- Chapter 13: Partition Generating Functions
- Chapter 14: Partition Identities
- Part IV: Geometric Number Theory
- Chapter 15: Lattice Points
- Appendices
- Appendix A: A proof that $\ds \lim_{n \mathop \to \infty} \map p n^{1/n} = 1$
- Appendix B: Infinite Series and Products
- Appendix C: Double Series
- Appendix D: The Integral Test
- Notes
- Suggested Reading
- Bibliography
- Hints and Answers to Selected Exercises
- Index of Symbols
- Index
Errata
Solution to Difference between Odd Squares is Divisible by 8
Chapter $2$: The Fundamental Theorem of Arithmetic:
- Since $a$ and $b$ are odd integers, $a = 2 r + 1$, and $b = 2 s + 1$. Thus
- $a^2 - b^2 = \paren {4 r^2 + 4 r + 1} - \paren {4 s^2 + 4 s + 1} = 4 \paren {r - s} \paren {r - s + 1}$.
- Now if $r - s$ is even, then $r - s = 2 m$ and $a^2 - b^2 = 8 m \paren {2 m + 1}$; if $r - s$ is odd, then $r - s = 2 n + 1$ and $a^2 - b^2 = 8 \paren {2 n + 1} \paren {n + 1}$. Thus in any case $a^2 - b^2$ is divisible by $8$ if $a$ and $b$ are odd integers.
Source work progress
- 1971: George E. Andrews: Number Theory ... (previous) ... (next): $\text {4-3}$ Riffling: Exercise $1$