Here is the chain of collaborations from Sylvain Hallé to Paul Erdös
in 4 papers.
Hallé, S., Hughes, G., Bultan, T., Alkhalaf, M. (2009).
Generating Interface Grammars from WSDL for Automated Verification of Web
Services. Proc. ICSOC 2009, Springer: Lecture Notes in Computer Science,
to appear in November 2009.
Ibarra, Oscar H.; Su, Jianwen; Dang, Zhe; Bultan, Tevfik; Kemmerer, Richard.
Counter machines: decidable properties and applications to verification
problems. Mathematical foundations of computer science 2000 (Bratislava),
426-435, Springer: Lecture Notes in Comput. Sci. 1893, 2000.
Ibarra, Oscar H.; Moran, Shlomo; Rosier, Louis E. A note on the
parallel complexity of computing the rank of order $n$ matrices.
Inform. Process. Lett. 11 (1980), no. 4-5, 162.
Erdös, P.; Linial, N.; Moran, S.
Extremal problems on permutations under cyclic equivalence.
Discrete Math. 64 (1987), no. 1, 1-11.
Prior to August 2009, my Erdös number was 5 through this chain of
papers:
Sylvain Hallé, Rudy Deca, Omar Cherkaoui, Roger Villemaire:
Automated
Validation of Service Configuration on Network Devices. Proc. MMNS 2004:
176-188
Christian Michaux, Roger Villemaire: Cobham's Ttheorem seen through
Büchi's Theorem. Proc. ICALP 1993: 325-334
Shai Ben-David, Klaus Meer, Christian Michaux: A Note on Non-complete
Problems in NPImage. J. Complexity 16(1): 324-332 (2000)
Noga Alon, Shai Ben-David, Nicolò Cesa-Bianchi, David Haussler:
Scale-sensitive Dimensions, Uniform Convergence, and Learnability. Proc.
FOCS 1993: 292-301
Noga Alon, Paul Erdös: Disjoint Edges in Geometric Graphs. Discrete
& Computational Geometry 4: 287-290 (1989)