Peter D. Schumer
With Introduction to Number Theory, author Peter Schumer tells the story of natural numbers and some of the interesting discoveries made about them over the centuries. The book contains a thoroughly up-to-date exposition of much of elementary number theory, with plenty of examples throughout to help illuminate how the principles actually apply in practice. Many examples are stated as problems with solutions, and the author encourages students to take a more active role by attempting to solve the problems themselves. To make the book accessible to a wide variety of students, the proofs are as direct as possible without requiring any abstract algebraic background.
Introduction to Number Theory