"Constructing Carmichael numbers through improved subset-product algorithms," co-authored with the late Red Alford, as well as Steven Hayman and Andrew Shallue, has been published on-line by Mathematics of Computation.
It looks like all of the 2013 issues of Math. Comp. are filled up, so this will probably be officially a 2014 paper once it appears in print.
As this is my first co-authored paper to be published, I now have a finite Erdős number, namely 3. (Red co-authored with Carl Pomerance and Andrew Granville, who each have an Erdős number of 1.)
(According to MathSciNet, this reduces Shallue's number from 4 to 3, and is Hayman's first paper. This paper, however, is not indexed by MathSciNet yet, which limits my ability to compute some collaboration distances that interest me, as well as raising the possibility that my co-authors have other un-indexed papers.)
I lost my chance at an Erdős number of 1 by deflecting his questions about what I was working on, but, well, I'm not really into Erdős-style collaborations, and I'm comfortable with my style of research.