Elementary Number Theory
by W W L Chen
Publisher: Macquarie University 2003
Number of pages: 98
An introduction to the elementary techniques of number theory: division and factorization, arithmetic functions, congruences, quadratic residues, sums of integer squares, elementary prime number theory, Gauss sums and quadratic reciprocity.
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by R. D. Carmichael - John Wiley & Sons
The purpose of this book is to give the reader a convenient introduction to the theory of numbers. The treatment throughout is made as brief as is possible consistent with clearness and is confined entirely to fundamental matters.
by Wissam Raji - The Saylor Foundation
These are notes for an undergraduate course in number theory. Proofs of basic theorems are presented in an interesting and comprehensive way that can be read and understood even by non-majors. The exercises broaden the understanding of the concepts.
by Allen Hatcher - Cornell University
An introductory textbook on elementary number theory from a geometric point of view, as opposed to the strictly algebraic approach. A fair amount of the book is devoted to studying Conway's topographs associated to quadratic forms in two variables.
by William Stein - Springer
Textbook on number theory and elliptic curves. It discusses primes, factorization, continued fractions, quadratic forms, computation, elliptic curves, their applications to algorithmic problems, and connections with problems in number theory.