Natural number > Catalogs > Special properties
From Citizendium, the Citizens' Compendium
- Prime number [r]: A number that can be evenly divided by exactly two positive whole numbers, namely one and itself. [e]
- Mersenne prime [r]: Add brief definition or description
- Fermat prime [r]: Add brief definition or description
- Pseudoprime [r]: Probable prime (an integer which shares a property common to all prime numbers) which is not actually prime. [e]
- Strong pseudoprime [r]: A composite number that passes a pseudoprimality test. [e]
- Fermat pseudoprime [r]: A composite number q such that aq − 1≡ 1 (mod q) for any a that is coprime with q and a is between 2 and q-2 [e]
- Euler pseudoprime [r]: A Fermat pseudoprime to at most 1/2 of all possible bases less than itself. [e]
- Perrin pseudoprime [r]: Add brief definition or description
- Carmichael number [r]: A composite number c such that ac−1 ≡ 1 (mod c) for all a that are coprime with c. [e]
- Figurative number [r]: Add brief definition or description
- Triangular number [r]: Represents the number of circles you can arrange to a equilateral triangle. [e]
- Fibonacci number [r]: Element of the sequence in which the first number is 0, the second number is 1, and each subsequent number is equal to the sum of the previous two numbers. [e]
- Lucas number [r]: Terms of the Fibonacci sequence whose first two terms are 2 and 1. [e] Lucas sequence [r]: A particular generalisation of sequences like the Fibonacci numbers, Lucas numbers, Pell numbers or Jacobsthal numbers. [e]
