An Introduction to Number Theory Harold Stark Possible homework exercises. I've looked through the exercises in the book and selected a bunch of them that look good for homework exercises. There are more here than I'll actually assign, but they look good, so I might use some of them on quizzes or tests. I'm substituting public-key cryptography for chapter 4's magic squares, so I'll have to come up with some exercises on public-key cryptography. Chapter 1 An introduction to number theory 1.1 An introduction to number theory 1.2 Some elementary properties of divisibility p. 14 Misc. exercises: 1, 2, 3, 4, 5, 8, 9 Chapter 2 The Euclidean algorithm and unique factorization 2.1 The Euclidean algorithm p. 25: 2, 3, 4, 5, 6, 11, 12, 13 2.2 The fundamenatal theorem of arithmetic p. 32: 5, 7, 8, 12, 13, 14, 15 2.3 Applications of the fundamental theorem p. 35: 1, 2 2.4 Multiplicative functions p. 43: 1, 2, 3, 5, 6, 7, 8 2.5 Linear Diophantine equations p. 47: 1-10, 12 p. 48 Misc. exercises: 2, 3, 7, 11 Chapter 3 Congruences 3.1 Introduction p. 54: 1-5, 7, 8, 10 3.2 Fundamental properties of congruences p. 63: 1, 2, 4, 5, 6, 8, 9, 10, 13, 17, 19-21, 35 3.3 Linear congruence equations p. 76: 1-3, 7-9, 11-13, 17, 20 3.4 Reduced residue systems and Euler's phi function p. 82: 1, 2, 4, 10 3.5 More on Euler's phi function p. 86: 1, 2, 6, 7 3.6 Polynomial congruences (We'll only survey this section.) 3.7 Primitive roots p. 106: 2, 4, 5, 9, 12 p. 108 Misc. exercises: 8, 12, 15, 24-26 Public-key cryptography Exercises yet to be selected Chapter 5 Diophantine equations 5.1 Introduction p. 148: 1, 4 5.2 The use of congruences in solving Diophantine equations p. 151: 3, 7, 11 5.3 Pythagorean triples p. 155: 1, 2, 7 5.4 Fermat's method of descent p. 161: 3, 4, 5 p. 162 Misc. exercises: 2, 5, 7 Chapter 6 Numbers, rational and irrational 6.1 Rational numbers p. 169: 3-6, 7, 8, 9 6.2 Irrational numbers p. 171: 1, 2, 3 6.3 Lieuville's theorem and transcendental numbers (We'll only survey section 6.3) p. 177 Misc. exercises: 3, 7 Chapter 7 Continued fractions from a geometric viewpoint 7.1 Introduction p. 185: 3, 5 7.2 The continued fraction algorithm p. 196: 4, 5-7 7.3 Computation of a(sub)n p. 208: 1-5, 8 7.4 The best approximations p. 221: 3, 7, 10 7.5 A commentary of proof by picture 7.6 Periodic continued fractions p. 238: 2-8, 11, 12 7.7 The Fermat-Pell equation and the continued fraction expansion of square roots p. 245: 1-3, 6-8, 11, 12 p. 246 Misc. exercises: 2, 7