Number Theory Web -  .

Active Elementary Number Theory - - Interactive (Javascript) expression of a number as a sum of two squares.

Application of Digital Root - - A test for the terms of a sequence being expressed by a polynomial, by Roupam Ghosh.

The Arithmetic Properties of Binomial Coefficients - - Activated text by Andrew Granville.

The Canadian Number Theory Association - - A loosely defined group of individuals, mainly in Canada, active in research in Number Theory.

Covers, Sumsets and Zero-sums - - A unified approach to covering systems, restricted sumsets and zero-sum problems by Zhi-Wei Sun.

Fermat's Little Theorem - - With notes on Carmichael numbers and the life of R.D. Carmichael.

Frequently Asked Questions - - Number Theory section of the sci.math FAQ list.

Hakmem Continued Fractions - - Some notes from the MIT collection. Includes Gosper's algorithms for CF arithmetic.

Infinite Series Theorem - - Addresses the question whether a series of rational functions converges to a rational number.

Integer Relations - - To determine linear integer dependence among numerical constants and to determine the minimal polynomial of an approximate algebraic number. Interactive or via email.

Introduction to Bernoulli Numbers - - A web article with a brief history and account of their relationship with the Riemann zeta function and Fermat's Last Theorem (HTML/PS).

Klein Polyhedra - - Examples and algorithms for computing Klein polyhedra, also known as Arnold sails or veils (voiles), by Keith Briggs.

Lehmer's Conjecture - - That the Mahler measure of an algebraic number is bounded away from 1. Pages by Michael Mossinghoff, UCLA.

L-Functions - - Classified by degree, then by level, then by eigenvalue, then by root number.

Linear Independence Measures for Logarithms of Algebraic Numbers - - Michel Waldschmidt. Cetraro summer school lectures, July 2000.

MathPages: Number Theory - - Kevin Brown's collection of sci.math postings related to number theory topics.

MathWorld Number Theory - - Index to articles in Eric Weisstein's MathWorld in the area of number theory.

A Mechanical Proof of Quadratic Reciprocity - - A paper by David M. Russinoff describing the use of the Boyer-Moore theorem prover in mechanically generating a proof of the Law of Quadratic Reciprocity. PS/PDF.

Noncommutative Geometry, Trace Formulae and the Zeroes of the Riemann Zeta Function - - Lecture notes by Alain Connes.

Number Theory - - Proofs along with equation solvers and graphical views written in Java.

Number Theory - - Dave Rusin's guide to number theory.

Number Theory Foundation - - Aims to collect donations from supporters of number theory and to disburse these donations to encourage research.

Number Theory Glossary - - Compiled by Robert Campbell.

On-Line Encyclopedia of Integer Sequences - - Given an integer sequence, find its name, and formula.

Online Seminar: Galois theory of p-Extensions - - Email seminar on "Galoissche Theorie der p-Erweiterungen" by Helmut Koch.

Other Maths - - A wide selection of number theory topics compiled by Jon Perry.

Some Highlights of Arithmetic Combinatorics - - Lecture notes and resources on combinatorial number theory by Terence Tao.

Some Number-Theoretical Constants - - Products of rational functions of p over primes, computed by Gerhard Niklasch and Pieter Moree.

Somos Polynomials - - Related to Somos sequences and elliptic theta functions.

The Somos Sequence Site - - Web resources for information on Somos sequences and related topics such as elliptic divisibility sequences.

Square-free Gaps - - Algorithm and source code for the calculation of square-free numbers and gaps.

Transcendental Numbers - - Maple worksheets, lecture notes and links to other resources by John Cosgrove.

The Valuation Theory Home Page - - A forum for all mathematicians who work in valuation theory or apply valuation theoretical results in their own field of research.

Vignettes on Automorphic and Modular forms, Representations, L-functions, and Number Theory - - By Paul Garrett.

Visible Structures in Number Theory - - By Peter Borwein and Loki Jörgenson. Recognising number patterns visually.

The Work of Robert Langlands - - Thesis, papers, manuscripts, letters and bibliography.

World Records for Numerical Palindromes - - The 196 Palindrome Quest and The Most Delayed Palindromic Number, by Jason Doucette.