Louis W. Shapiro

2.1k total citations · 1 hit paper
57 papers, 1.3k citations indexed

About

Louis W. Shapiro is a scholar working on Discrete Mathematics and Combinatorics, Algebra and Number Theory and Computational Theory and Mathematics. According to data from OpenAlex, Louis W. Shapiro has authored 57 papers receiving a total of 1.3k indexed citations (citations by other indexed papers that have themselves been cited), including 41 papers in Discrete Mathematics and Combinatorics, 22 papers in Algebra and Number Theory and 19 papers in Computational Theory and Mathematics. Recurrent topics in Louis W. Shapiro's work include Advanced Combinatorial Mathematics (40 papers), Advanced Mathematical Identities (21 papers) and semigroups and automata theory (10 papers). Louis W. Shapiro is often cited by papers focused on Advanced Combinatorial Mathematics (40 papers), Advanced Mathematical Identities (21 papers) and semigroups and automata theory (10 papers). Louis W. Shapiro collaborates with scholars based in United States, South Korea and China. Louis W. Shapiro's co-authors include Wen-Jin Woan, Leon C. Woodson, Gi‐Sang Cheon, Emeric Deutsch, Hana Kim, Joseph E. Bonin, Rodica Simion, A. B. Stephens, Tian-Xiao He and Robert A. Sulanke and has published in prestigious journals such as Journal of Applied Physics, Applied Mathematics and Computation and American Mathematical Monthly.

In The Last Decade

Louis W. Shapiro

54 papers receiving 1.2k citations

Hit Papers

The Riordan group 1991 2026 2002 2014 1991 100 200 300
What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

  1. The Riordan group
    1991 317 citations Louis W. Shapiro, Wen-Jin Woan et al. Discrete Applied Mathematics profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Louis W. Shapiro United States 18 1.0k 613 290 262 257 57 1.3k
Gérard Viennot France 13 780 0.8× 441 0.7× 271 0.9× 273 1.0× 324 1.3× 19 1.1k
Emeric Deutsch United States 18 575 0.6× 330 0.5× 590 2.0× 159 0.6× 398 1.5× 79 1.2k
William Y. C. Chen China 16 505 0.5× 469 0.8× 223 0.8× 110 0.4× 189 0.7× 99 905
Richard Ehrenborg United States 16 593 0.6× 369 0.6× 240 0.8× 150 0.6× 420 1.6× 84 909
Sylvie Corteel France 17 711 0.7× 582 0.9× 117 0.4× 232 0.9× 160 0.6× 68 1.0k
Tatsuro Ito Japan 20 1.1k 1.1× 523 0.9× 233 0.8× 170 0.6× 735 2.9× 46 1.5k
Gilbert Labelle Canada 12 292 0.3× 167 0.3× 290 1.0× 190 0.7× 246 1.0× 60 792
Jay R. Goldman United States 16 316 0.3× 234 0.4× 170 0.6× 131 0.5× 204 0.8× 31 871
A. Karrass Canada 14 734 0.7× 298 0.5× 637 2.2× 917 3.5× 1.6k 6.2× 29 2.1k
D. Solitar Canada 15 818 0.8× 329 0.5× 703 2.4× 1.0k 3.8× 1.7k 6.7× 35 2.4k

Countries citing papers authored by Louis W. Shapiro

Since Specialization
Citations

This map shows the geographic impact of Louis W. Shapiro's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Louis W. Shapiro with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Louis W. Shapiro more than expected).

Fields of papers citing papers by Louis W. Shapiro

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Louis W. Shapiro. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Louis W. Shapiro. The network helps show where Louis W. Shapiro may publish in the future.

Co-authorship network of co-authors of Louis W. Shapiro

This figure shows the co-authorship network connecting the top 25 collaborators of Louis W. Shapiro. A scholar is included among the top collaborators of Louis W. Shapiro based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Louis W. Shapiro. Louis W. Shapiro is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Shapiro, Louis W., et al.. (2023). An invitation to the Riordan group. 4(3). Article #S2S1–Article #S2S1. 1 indexed citations
2.
He, Tian-Xiao & Louis W. Shapiro. (2020). Palindromes and pseudo-involution multiplication. Linear Algebra and its Applications. 593. 1–17. 3 indexed citations
3.
Shapiro, Louis W., et al.. (2017). Constructing Pseudo-Involutions in the Riordan Group.. 20. 6 indexed citations
4.
Shapiro, Louis W., et al.. (2015). The Boundary of Ordered Trees.. 18.
5.
Cheon, Gi‐Sang, Hana Kim, & Louis W. Shapiro. (2012). Combinatorics of Riordan arrays with identical A and Z sequences. Discrete Mathematics. 312(12-13). 2040–2049. 41 indexed citations
6.
Cheon, Gi‐Sang & Louis W. Shapiro. (2011). The uplift principle for ordered trees. Applied Mathematics Letters. 25(6). 1010–1015. 2 indexed citations
7.
Cheon, Gi‐Sang, Hana Kim, & Louis W. Shapiro. (2010). An algebraic structure for Faber polynomials. Linear Algebra and its Applications. 433(6). 1170–1179. 11 indexed citations
8.
Cheon, Gi‐Sang, Hana Kim, & Louis W. Shapiro. (2010). The hitting time subgroup, Łukasiewicz paths and Faber polynomials. European Journal of Combinatorics. 32(1). 82–91. 4 indexed citations
9.
Shapiro, Louis W., et al.. (2009). A Bijection Between 3-Motzkin Paths and Schroder Paths With No Peak at Odd Height. Journal of integer sequences. 12(3). 4 indexed citations
10.
Cheon, Gi‐Sang, et al.. (2009). Riordan group involutions and the Δ-sequence. Discrete Applied Mathematics. 157(8). 1696–1701. 14 indexed citations
11.
Shapiro, Louis W., et al.. (2007). On Sequences G n Satisfying G n = (d + 2)G n 1 G n 2. Journal of integer sequences. 10(8). 81. 1 indexed citations
12.
Cheon, Gi‐Sang & Louis W. Shapiro. (2007). Protected points in ordered trees. Applied Mathematics Letters. 21(5). 516–520. 23 indexed citations
13.
Cheon, Gi‐Sang, Hana Kim, & Louis W. Shapiro. (2007). Riordan group involutions. Linear Algebra and its Applications. 428(4). 941–952. 38 indexed citations
14.
Chen, William Y. C., et al.. (2005). Parity reversing involutions on plane trees and 2-Motzkin paths. European Journal of Combinatorics. 27(2). 283–289. 9 indexed citations
15.
Shapiro, Louis W.. (2003). Bijections and the Riordan group. Theoretical Computer Science. 307(2). 403–413. 67 indexed citations
16.
Shapiro, Louis W.. (1992). Random walks with absorbing points. Discrete Applied Mathematics. 39(1). 57–67. 2 indexed citations
17.
Shapiro, Louis W., et al.. (1982). Product-weighted lead codes revisited. Journal of Combinatorial Theory Series A. 33(1). 112–116. 1 indexed citations
18.
Shapiro, Louis W., et al.. (1977). Motzkin numbers. Journal of Combinatorial Theory Series A. 23(3). 291–301. 113 indexed citations
19.
Shapiro, Louis W.. (1976). A Catalan triangle. Discrete Mathematics. 14(1). 83–90. 111 indexed citations
20.
Shapiro, Louis W.. (1976). A short proof of an identity of Touchard's concerning catalan numbers. Journal of Combinatorial Theory Series A. 20(3). 375–376. 18 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

Explore authors with similar magnitude of impact

Breakdown of academic impact, for papers by Gérard Viennot Breakdown of academic impact, for papers by Emeric Deutsch Breakdown of academic impact, for papers by William Y. C. Chen Breakdown of academic impact, for papers by Richard Ehrenborg Breakdown of academic impact, for papers by Sylvie Corteel Breakdown of academic impact, for papers by Tatsuro Ito Breakdown of academic impact, for papers by Gilbert Labelle Breakdown of academic impact, for papers by Jay R. Goldman Breakdown of academic impact, for papers by A. Karrass Breakdown of academic impact, for papers by D. Solitar
Rankless by CCL
2026