decimal expansion
41Repunit — In recreational mathematics, a repunit is a number like 11, 111, or 1111 that contains only the digit 1. The term stands for repeated unit and was coined in 1966 by A.H. Beiler. A repunit prime is a repunit that is also a prime… …
42diagonal procedure — The method first used by Cantor to show that there cannot be an enumeration of the real numbers. Any real number can be written as an infinite decimal. So we imagine a correspondence with the natural numbers, giving us some real as the first,… …
43Computable function — Total recursive function redirects here. For other uses of the term recursive function , see Recursive function (disambiguation). Computable functions are the basic objects of study in computability theory. Computable functions are the formalized …
44Sophie Germain prime — In number theory, a prime number p is a Sophie Germain prime if 2 p + 1 is also prime. For example, 23 is a Sophie Germain prime because it is a prime and 2 times; 23 + 1 = 47, also prime. These numbers are named after French mathematician Marie… …
451000 (number) — List of numbers Integers ← 1k 2k 3k 4k 5k 6k 7k 8k 9k → Cardinal 1000 one thousand …
46Happy number — A happy number is defined by the following process. Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a… …
47Feynman point — The Feynman point is the sequence of six 9s which begins at the 762nd decimal place of π. It is named after physicist Richard Feynman, who once stated during a lecture he would like to memorize the digits of π until that point, so he could recite …
48Complete metric space — Cauchy completion redirects here. For the use in category theory, see Karoubi envelope. In mathematical analysis, a metric space M is called complete (or Cauchy) if every Cauchy sequence of points in M has a limit that is also in M or,… …
49Prime constant — The prime constant is the number ho whose nth binary digit is 1 if n is prime and 0 if it is composite.In other words, ho is simply the number whose binary expansion corresponds to the indicator function of the set of prime numbers. That is, : ho …
50List of common misconceptions — This incomplete list is not intended to be exhaustive. This is a list of current, widely held, false ideas and beliefs about notable topics which have been reported by reliable sources from around the world. Each has been discussed in published… …
