Imagine Math pp 175-185 | Cite as

Waiting for ABRACADABRA. Occurrences of Words and Leading Numbers

  • Emilio De Santis
  • Fabio Spizzichino


In this paper we introduce the readers to the concept of “leading number”, as proposed by J. H. Conway in the seventies of the last century. The leading number, associated to a word w, is a binary vector that describes some special aspects of the structure of w. We shall see that it conveys the essential information that is needed in the analysis of the time of occurrence of w in a random sequence of letters.


Random Sequence Integer Number Applied Probability Discrete Random Variable Classical Topic 
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Copyright information

© Springer-Verlag Italia 2012

Authors and Affiliations

  • Emilio De Santis
    • 1
  • Fabio Spizzichino
    • 1
  1. 1.Department of MathematicsSapienza University of RomeItaly

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