Number Theory
- 181
- Classical Modular Polynomials
- Tables of modular polynomials Phi_l for prime l to 270, computed by Michael Rubinstein. Gzipped text and specially compressed formats.
- 184
- Iwasawa Invariants of Elliptic Curves
- For each curve (labelled as in Cremona) the mu and lambda-invariants are listed for the primes between 2 and 17. By Robert Pollack.
- 185
- Rational Points on Elliptic Curves
- A wide collection of known integer solutions to elliptic curves and their corresponding Diophantine equations, presented by Hisanori Mishima.
- 187
- Digital Divisibility Tests
- From Carlos Rivera's Prime Puzzles and Problems collection. Carlos asks for the general divisibility rules for any prime number.
- 188
- Divisibility Tests
- From the Furman University Electronic Journal of Undergraduate Mathematics. Apoorva Khare's paper is available as an abstract, DVI, and PostScript.
- 189
- Explaining the Divisibility Rules
- Proof of the elementary division rules, plus some lesser-known rules for larger divisors and other bases.
- 191
- Aliquot Sequences
- Results and software from Paul Zimmermann, addressing the Catalan Conjecture and working on the difficult "Lehmer Five" sequences.
- 192
- Aliquot Sequences
- Aliquot sequences arise in iterating the sum-of-divisors function s. Bosma has calculated tables up to start value 50,000 and 80 digits.
- 193
- Aliquot Sequences
- Statistics by Wolfgang Creyaufmueller, including many tables and links to factoring sites and software.
- 194
- Amicable Numbers
- Observations on amicable pairs and their distribution, including Harshad and Happy Amicable pairs.
- 195
- Multiply Perfect Numbers
- Up-to-date information on multiperfect numbers and searchable database maintained by Achim Flammenkamp.
- 196
- Perfect Numbers
- A detailed history of the quest for perfect numbers, from Euclid to their present-day Mersenne discoveries.
- 197
- Brilliant Numbers
- Tables of maximal and minimal numbers with two, three or four prime factors of the same length (in decimal notation).
- 198
- Factorization Results
- Tables, summaries, and links to many factoring endeavors, including primorials, factorials, and cyclotomic polynomials. Includes theorems and descriptions behind each project.