I was reading up on Gegenbauer polynomials for a blog post about the kissing number problem, which I also asked a separate question about later.
On the Wolfram MathWorld plot summary for Gegenbauer polynomials, toward the bottom, there is a list of "See Also" topics. This list includes the birthday problem.
I don't see any connection between the two topics. Visiting the plot summary for the birthday problem doesn't yield anything about Gegenbauer polynomials that I can see. (As Dietrich Burde notes in the comments, however, it does link to hypergeometric functions, which in turn link to Gegenbauer polynomials.) Am I missing something, or is this perhaps a mistake?