Preface for “Combinatorics, Riordan Matrices and Umbral Calculus—In Memory of Professor Emanuele Munarini”

This editorial introduces the Special Issue of Mathematics “Combinatorics, Riordan Matrices and Umbral Calculus—in Memory of Professor Emanuele Munarini,” which collects ten peer-reviewed papers on theoretical and applied aspects of enumerative combinatorics, combinatorial matrices, and polynomial sequences. The contributions cover a variety of topics and methods, including generating functions, Riordan arrays, recurrence relations, and related combinatorial structures. The Special Issue’s scope and individual contributions are briefly discussed.