My Erdös number is equal to 3:
1. B. Brindza, P. Erdös. On some diophantine problems involving
powers and factorials. J. Aust. Math. Soc., Ser. A 51, No.1, 1-7 (1991).
MR1119683
2. A. Borbély, V. Bovdi, B. Brindza, T. Krausz. Covering
theorems for Artinian rings. Publ. Math. Debrecen 51, No.3-4, 323-329 (1997).
MR1485227
3. V. Bovdi, A. Konovalov.
Integral group ring of the first Mathieu simple group.
In Groups St. Andrews 2005. Vol. I,
volume 339 of London Math. Soc. Lecture Note Ser., 237-245.
Cambridge Univ. Press, Cambridge, 2007.
MR2328163