Louis Welles Shapiro (born 1941) is an American mathematician working in the fields of

combinatorics Combinatorics is an area of mathematics primarily concerned with counting, both as a means and an end in obtaining results, and certain properties of finite structures. It is closely related to many other areas of mathematics and has many appl ...

and finite group theory. He is an emeritus professor at Howard University. Shapiro attended Harvard University for his undergraduate studies and then the University of Maryland, College Park for graduate school. Shapiro is most known for introducing the

Riordan array A Riordan array is an infinite lower triangular matrix, D, constructed out of two formal power series, d(t) of order 0 and h(t) of order 1, in such a way that d_ = ^n(t) h(t)^k. A Riordan array is an element of the Riordan group. It was ...

, named after mathematician John Riordan, and developing the theory around it. He has been an organizer of and speaker at the annual International Conference on Riordan Arrays and Related Topics, which has been held annually beginning 2014.

References

1941 births Living people 20th-century American mathematicians 21st-century American mathematicians Howard University faculty Harvard University alumni University of Maryland, College Park alumni {{US-mathematician-stub