Okay, it might be a joke among mathematicians – but it is nice to know that one has a finite Erdős Number. Wolfram MathWorld describes it as…

…the number of “hops” needed to connect the author of a paper with the prolific late mathematician Paul Erdős. An author’s Erdős number is 1 if he has co-authored a paper with Erdős, 2 if he has co-authored a paper with someone who has co-authored a paper with Erdős, etc. (Hoffman 1998, p. 13).

In my case, the following collaboration path results in an Erdős number of 3… 🙂

• Kai C. Bader and Mikhail J. Atallah and Christian Grothoff “Efficient relaxed search in hierarchically clustered sequence datasets”, ACM J. Exp. Algorithmics, 17(1):1.4:1.1–1.4:1.18. 2012.
• Mikhail J. Atallah and Samuel S. Wagstaff, “Watermarking Data Using Quadratic Residues”, Proc. of SPIE Workshop on Electronic Imaging (SPIE 99), SPIE – The International Society for Optical Engineering, SPIE Vol. 3657, pages 283-288, 1999.
• Paul Erdos and Samuel S. Wagstaff, “The Fractional Parts of the Bernoulli Numbers”, Illinois J. Math. 24, pages 104-112, 1980.