A dyadic distribution is a probability distribution whose probability mass function is
where x i {\displaystyle x_{i}} is some whole number.
It is possible to find a binary code defined on this distribution, which has an average code length that is equal to the entropy.1
Cover, T.M., Joy A. Thomas, J.A. (2006) Elements of information theory, Wiley. ISBN 0-471-24195-4 /wiki/ISBN_(identifier) ↩