This started as an idle Sunday afternoon project to find out what my Erdos number is.

It turns out I know someone with an Erdos number of 2.

*Hajo J. Broersma coauthored with Dieter Kratsch (MR1616232)Dieter Kratsch coauthored with Paul Erdös (MR1133813 (92i:05118))*

Unfortunately I haven’t co-authored any papers with Hajo and as far as I can tell nobody I know has co-authored a paper with him so that turned out to be a bit of a dead-end (although if we stretch the rules a bit I’m sure that Malcolm and Hajo have signed Durham University forms together at some point giving me an Erdos number of 4)

My ex-boss and PhD external advisor, Jie Xu, has collaborated with Victor Winter who has an Erdös number of 5 giving him an Erdos number of 6, which gives me an Erdos number of 7…

*Victor L. Winter coauthored with Mahadevan Subramaniam (MR2113317)Mahadevan Subramaniam coauthored with Deepak Kapur (MR1390905 (97a:68144))Deepak Kapur coauthored with Robert McNaughton (MR0785910 (86j:03037))Robert McNaughton coauthored with Yechezkel Zalcstein (MR0374301 (51 #10501))Yechezkel Zalcstein coauthored with Paul Erdös (MR0881175 (88d:05092))*

…but it appears I can do a little better than this.

I collaborated on an AHM paper with Jin Peng Huai from Beihang University (through the CoLaB project). Prof. Huai has an Erdos number of 5, which gives me an Erdos number of 6…

*Jin Peng Huai coauthored with Da-Zhi Sun (MR2339778)Da-Zhi Sun coauthored with Zhen Fu Cao (MR2135011 (2005k:94026))Zhen Fu Cao coauthored with Maurice Mignotte (MR1843317 (2002i:11032))Maurice Mignotte coauthored with Tarlok N. Shorey (MR0743965 (85f:11007))Tarlok N. Shorey coauthored with Paul Erdös (MR0419381 (54 #7402))*

…but finally I have another more verifiable route to an Erdos number.

It turns out that my PhD supervisor, Malcolm Munro, has an Erdos number of 5 according to the MathSciNet Collaboration Distance calculator through a paper published with Mark Harman. Which would also give me an Erdos number of 6 since I’ve written papers with Malcom…

*Malcolm Munro coauthored with Mark Harman (MR2062303)Mark Harman coauthored with Robert M. Hierons (MR1935710 (2003h:68037))Robert M. Hierons coauthored with Bill Jackson (MR1617958 (99e:05032))Bill Jackson coauthored with John Adrian Bondy (MR0821518 (87g:05137))John Adrian Bondy coauthored with Paul Erdös (MR0317991 (47 #6540))*

…but if you delve a little deeper, Malcolm published a paper with Rob Hierons in ICSM’2002 which gives Malcolm an Erdos number of 4, which makes mine 5.

So as far as I can tell at this point my Erdos number is 5, not bad for someone who failed their math’s ‘A’ Level. Of course the fact that I’ve published any papers is a constant source of amazement to me anyway.

10th April 2014

And so many years later (bored in a hotel room) it turns out that Microsoft now do a tool for calculating Erdos numbers. Turns out my Erdos number is 4. Even more amazing.

Malcom Munro coauthored with Pak Chin Li

Pak Chin Li coauthored with Douglas Stinson

Douglas Stinson coauthored with Paul Erdös