An Introductory Course in Elementary Number Theory
by Wissam Raji
Publisher: The Saylor Foundation 2013
Number of pages: 171
These notes serve as course 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 are carefully chosen to broaden the understanding of the concepts.
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by Joseph H. Silverman - Pearson Education, Inc.
Introductory undergraduate text designed to entice non-math majors into learning some mathematics, while at the same time teaching them how to think mathematically. The exposition is informal, with a wealth of examples that are analyzed for patterns.
by W W L Chen - Macquarie University
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.
by William Edwin Clark - University of South Florida
One might think that of all areas of mathematics arithmetic should be the simplest, but it is a surprisingly deep subject. It is assumed that students have some familiarity with set theory, calculus, and a certain amount of mathematical maturity.
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The substance of all that has been written on this subject by Nicomachus, Iamblichus, and Boetius, together with some particulars respecting perfect, amicable, and other numbers, which are not to be found in the writings of modern mathematicians.