Preface.- 1. On the Number of Dot Product Chains in Finite Fields and Rings (V. Blevins, D. Crosby, E. Lynch, S. Senger).- 2. Completeness of Positive Linear Recurrence Sequences (E. Boldyriew, J. Haviland, P. Lam, J. Lentfer, S.J. Miller, F.T. Suarez).- 3. Length Density and Numerical Semigroups (C. Brower, S. Chapman, T. Kulhanek, J. McDonough, C. O'Neill, V. Pavlyuk, V. Ponomarenko).- 4. On a Problem of Cilleruelo-Nathanson, II (Y.-G. Chen, J. Fang).- 5. Linked Partition Ideals and a Schur-type Identity of Andrews (S. Chern).- 6. Semi-magic Matrices for Dihedral Groups (R. Donley).- 7. Is the Syracuse Falling Time Bounded by 12? (S. Eliahou, J. Fromentin, R. Simonetto).- 8. Genera of Numerical Semigroups and Polynomial Identities for Degrees of Syzygies (L. Fel).- 9. Expansion, Divisibility, and Parity (H.A. Helfgott).- 10. Sums of Squares (R.J. Hendel).- 11. Bilinear Generalized Radon Transforms in the Plane (A. Greenleaf, A. Iosevich, B. Krause, A. Liu).- 12. GeneralizedBernoulli Numbers, Cotangent Power Sums, and Higher-order Arctangent Numbers (B. Isaacson).- 13. A New Class of Minimal Asymptotic Bases (M.B. Nathanson).- 14. An Inverse Problem for Infinite Sidon Sets (M.B. Nathanson).
