Odious number

A kind of number

About Odious number

An odious number is a non-negative integer that has an odd number of 1s in its binary expansion. The complement of evil numbers (which have an even number of 1s).

Key features

  • 1, 2, 4, 7, 8, 11, 13, 14, … are odious.
  • Every positive integer is either evil or odious.

Examples:

1, 2, 4, 7, 8, 11, 13, 14

Further reading