The p-adic valuation of k-central binomial coefficients
  The coefficients c(n,k) defined by (1-k^2x)^(-1/k) = sum c(n,k) x^n reduce to the central binomial coefficients for k=2. Motivated by a question of H. Montgomery and H. Shapiro for the case k=3, we prove that c(n,k) are integers and study their divisibility properties. 
Armin Straub, Tewodros Amdeberhan, Victor H. Moll