For other uses of “evil” in mathematics, see evil.
transfinite arithmetic, cardinal arithmetic, ordinal arithmetic
prime field, p-adic integer, p-adic rational number, p-adic complex number
arithmetic geometry, function field analogy
In number theory, an evil number is a natural number that has an even number of ones in its binary radix expansion.
The term “evil number” was chosen by the authors of Berlekamp, Conway, & Guy 2001 because the two first letters of “evil” were the same as that of “even number”.
Wikipedia, Evil number
Neil Sloane, Sequence A001969 (Evil numbers: numbers with an even number of 1’s in their binary expansion), The On-Line Encyclopedia of Integer Sequences, OEIS Foundation [web]
Elwyn R. Berlekamp, John H. Conway, Richard K. Guy, Winning Ways for Your Mathematical Plays, Volume 1, 2nd ed., A K Peters, 2001, chapter 14, p. 110. [ISBN:978-1568811307]
Jean-Paul Allouche, Benoit Cloitre?, Vladimir Shevelev, Beyond odious and evil [arXiv:1405.6214]
Last revised on May 18, 2025 at 16:51:59. See the history of this page for a list of all contributions to it.