**Seymour (Sy) Schuster** passed away on October 31, 2020, at the age of 94, after testing positive for COVID-19. He was the Laird Professor of Mathematics and the Liberal Arts, Emeritus, at Carleton College (retired in 1994). He was also a life member of the MAA, maintaining his membership for 72 years! Schuster is considered one of the fathers of mathematics research by undergraduates, as he co-convened a conference on the concept, at Carleton in 1961 with Kenneth O. May. He also created the College Geometry Project in the 1960’s, which included well-received instructional videos for teachers. More information about Schuster’s life and career can be found in a remembrance from Carleton College, an extensive memorial site, and his obituary.

**Janet Liou-Mark** passed away on September 6, 2020, at the age of 54. She was a Professor of Mathematics at New York City College of Technology of the City University of New York for 22 years and a member of the MAA for six years. An expert in mathematics education, Liou-Mark was a founding member of the Peer-Led TeamLearning International Society (PLTIS) which fosters learning through peer-led teams. In 2014, she was the recipient of the MAA’s Metropolitan New York Section 2014 Award for Distinguished Teaching of Mathematics and the 2019 Award for Distinguished Service from the section. Liou-Mark was the Chair of the Metropolitan New York Section of the MAA from 2018 to August 2020. More information about Liou-Mark’s career can be found in this remembrance from the PLTIS and her faculty profile.

**Ranjan Roy** died unexpectedly on August 12, 2020, at the age of 73. He was the Huffer Professor of Mathematics and Astronomy at Beloit College, posthumously promoted to emeritus status after his passing. Roy was known for his expertise in differential equations, fluid mechanics, special functions, Fuchsian groups, and the history of mathematics. He was a member of the MAA for 31 years, and the recipient of several MAA awards: the teaching award from the Wisconsin Section, the 2003 Deborah and Franklin Tepper Haimo Award for excellence in teaching, and the 1991 Carl B. Allendoerfer Award for the expository article “The Discovery of the Series Formula for π”. More information about his life and career can be found in “A Teacher Who Transformed Lives” from Beloit College, a remembrance also published by Beloit College, and his obituary.

**Harold Don Allen** passed away on July 11, 2020, at the age of 89. He was a member of the MAA for 52 years. With a doctorate in mathematics education, he taught professionally for 51 years (retiring in 1987) as a high school teacher in greater Montreal and remote Quebec, and as a professor of mathematics education at the Nova Scotia Teachers College in Truro. Allen was well-known for his contributions to McGill University’s Summer School for the Gifted and Ottawa’s Bright Math Camps in the 1990s, as well as work educating the Canadian public in the 1970’s about the merits of the metric system. He was also active in numismatic societies, bringing a “story-teller’s passion to curation of numismatic history”, including his use of television. More information about Allen’s life and career can be found in a remembrance from McGill, this commentary, and his obituary.

**Peter Duren** passed away on July 10, 2020, at the age of 85. He was a professor emeritus of mathematics at the University of Michigan in Ann Arbor and a member of the MAA for 62 years. Duren was an expert in complex analysis, publishing several books in the field, including Invitation to Classical Analysis. He served on the editorial board of The American Mathematical Monthly from 1996 to 2001, and Duren was the son of past MAA president William L. Duren Jr. More information about his life and career can be found in his obituary.

**Ronald (Ron) Graham** passed away on July 6, 2020, at the age of 84. He was a former president of the MAA (2003-04) and a life member, maintaining his membership for 64 years. Graham was a central figure for over half a century in the development of discrete mathematics, making seminal contributions to scheduling theory, computational geometry, and other areas. He also popularized the concept of theErdős number. Graham received numerous awards from the MAA: the Carl B. Allendoerfer Award (1990) and the Lester R. Ford Award (1991), which are two MAA awards for articles of expository excellence, and the Euler Book Prizewith Persi Diaconis for their book Magical Mathematics. An account of his many other honors from various societies can be found on his Wikipedia page. Graham was also a former president of the AMS (1993-94) and was honored with their Leroy P. Steele Prize for lifetime achievement as a research mathematician. He was the former president of the International Jugglers Association, and during his career he developed new juggling routines utilizing concepts from discrete mathematics. Graham spent the primary part of his career at Bell Labs/AT&T Labs, and then joined the University of California, San Diego (UCSD) for several years. For more about Graham’s life and his work, start with the remembrance published in MAAFOCUS, an article from UCSD establishing an endowed chair in his name, a remembrance from UCSD, the citation from the AMS, a follow-up article from the AMS, video tributes from the combinatorics community, and an article in The Guardian.

**Enrico Federighi** passed away on May 5, 2020, at the age of 92. He was a mathematician for the Johns Hopkins University Applied Physics Laboratory retiring after 38 years of service, and a member of the MAA for 60 years. More information about his life and career can be found in his obituary.

**John H. Conway** passed away of complications from COVID-19, on April 11, 2020, at the age of 82. Conway’s contributions to mathematics were wide and deep, as he made seminal contributions to combinatorial game theory, number theory, geometry, topology, algebra, and other areas. Among his well-known discoveries or inventions are the Conway group, his Game of Life, and surreal numbers. He received numerous prizes, and to name a few: he was the first recipient of the Pólya Prize of the London Mathematical Society; he was awarded the AMS’ Leroy P. Steele Prize for Mathematical Exposition; and he was a fellow of the American Academy of Arts and Sciences. At Princeton University, Conway was the John von Neumann Professor in Applied and Computational Mathematics until 2013, when he acquired emeritus status. To learn more about Conway’s life and his work, start with his Wikipedia page (written by Siobhan Roberts), a remembrance from Princeton University, a reflection from Scientific American, and his obituary in The New York Times. There is also an xkcd tribute and a commentary with links to MAA articles from Don Albers. Conway and his work are featured on many MAA pages.

**Cecil Rousseau** passed away on April 10, 2020, at the age of 82. He was Emeritus Professor at the University of Memphis and a member of the MAA for 50 years. Known as C²R (“C-squared-R”) to students and colleagues, Rousseau played a major role in the establishment, growth, and success of the U.S. Mathematical Olympiad Team. He led the USA International Mathematical Olympiad delegation for several years in the 1980’s and 1990’s, including the 1986 team that tied the Soviet Union for first place. In 2012, Rousseau received the prestigious Paul Erdös Award, and he was Erdős' 5th most common co-author, with 35 joint papers. Rousseau served as the Managing Editor for the Problems Section of SIAM Review. For the MAA, he served on the USAMO/USAJMO board for mathematics competitions, the College Mathematics Journal editorial board, and the Committee on Competitions. More information about Rousseau’s life and career can be found in this remembrance from the University of Memphis, an older U-M article and his obituary.

**Carl E. Behrens, Jr.** passed away on March 19, 2020, at the age of 87. He was an energy policy analyst with the Library of Congress’s Congressional Research Service from 1975 to 2014, and a member of the MAA for 18 years. Between 2008 and 2019, Behrens served two terms as Chair of the SIGMAA on the Philosophy of Mathematics, as well as two terms as its Program Director. Among a variety of talks and sessions at national meetings, he spoke on “What are mathematical objects: An empiricist hypothesis” in 2006. Behrens was the co-editor ofUsing the Philosophy of Mathematics in Teaching Undergraduate Mathematics, part of the MAA Notes series.

**Harlan Koca** passed away on March 10, 2020, at the age of 89. He was a professor emeritus at Washburn University in Topeka and a member of the MAA for 51 years. More information about his life and career, including comments from students, can be found in his obituary.

**Richard K. Guy** passed away on March 9, 2020, at the age of 103. He was emeritus professor at the University of Calgary and a member of the MAA for 52 years. Guy published more than 300 papers and 12 books in areas such as number theory, geometry, recreational mathematics, combinatorics, and graph theory. He is well-known as the co-author of Winning Ways for your Mathematical Plays (with John Conway and Elwyn Berlekamp) and the author of Unsolved Problems in Number Theory. A new book, The Unity of Combinatorics, written with Ezra (Bud) Brown, was published posthumously in the spring of 2020. A remembrance from the University of Calgary includes the following observation: “Though he was undoubtedly preeminent in his field, he strove to make mathematics accessible to all.” Guy was a lifetime member of the MAA and received the MAA’s Lester R. Ford Award in 1989 for his paper “The Strong Law of Small Numbers”. To learn more about Guy’s life and career, start with a commentary with links to MAA articles from Don Albers and tributes to Guy published in MAA FOCUS. The Canadian Climbing League also published tribute, as Guy was also an avid climber. Further information can be found in his obituary.

**Katherine Johnson** passed away on February 24, 2020, at the age of 101. Johnson was the main character of theHidden Figures book and movie which chronicled the successes of African-American women who were “human computers” at NASA during the “space race” of the 20th century. Johnson worked for NASA from 1952 to 1986 and was critical to the success of manned US space flights, especially the historical missions of the 1960’s. For NASA, she made the necessary calculations in orbital mechanics (e.g. trajectories, launch windows) for missions to succeed, and, as reported in TheWashington Post, in 26 signed reports for the space agency, and in many more papers that bore others’ signatures on her work, she codified mathematical principles that remain at the core of human space travel.” Johnson was awarded the Presidential Medal of Freedom by President Obama in 2015. Significantly more information about her life and career can be found in an article in anNPR article, an article in the Philadelphia Tribune, and her obituary.

**Otis B. McCowan** passed away on February 24, 2020, at the age of 85. He was a professor emeritus of mathematics at Belmont University and a member of the MAA for 55 years. He was remembered as an excellent professor and a supporter of Belmont athletics. More information about his life and career can be found in his obituary.

**Reuben Hersh** passed away on January 3, 2020, at the age of 92. He was Professor Emeritus at the University of New Mexico and a member of the MAA for 57 years. Hersh was best known for his work in the history and philosophy of mathematics, and Hersh and Philp J. Davis won the National Book Award in 1983 forThe Mathematical Experience. They also co-authored Descartes’ Dream: The World According to Mathematics. Hersh was also the recipient of the MAA’s Chauvenet Prize in 1975 (with Martin Davis) for an article inScientific American, as well as the MAA’s Lester R. Ford Award in 1994 (with Edgar Lorch). Hersh served on the College Mathematics Journal board for many years. More information about his life and career can be found in a tribute from the Santa Fe Institute, and his obituary.