"Ji Chen" can refer to various things depending on the context, such as a person's name, a location, or even a concept. If you're referring to a specific individual, Ji Chen could be a common name in Chinese-speaking communities. Conversely, "Ji Chen" could also refer to a concept or a product in certain contexts, such as literature, technology, or entertainment.

A Riesel number is a natural number \( k \) such that there exists an integer \( n \) for which the expression \( n \times 2^n - k \) is composite for all integers \( n \) greater than or equal to some starting point \( N \).

A Smarandache-Wellin number is a special type of integer that is defined in relation to the properties of digits in its decimal representation.

The Ulam spiral, also known as the Ulam spiral or prime spiral, is a graphical depiction of the prime numbers, named after the mathematician Stanislaw Ulam, who first created it in 1963. To construct the Ulam spiral, you start by placing the natural numbers in a spiral pattern on a two-dimensional grid.

David A. Freedman (1938–2008) was a prominent American statistician known for his significant contributions to the field of statistics, particularly in areas such as Bayesian statistics, statistical modeling, and survey sampling. He was a professor at the University of California, Berkeley, and was noted for his work in promoting the importance of rigorous statistical methods and practical applications in various domains.

Alexander van Oudenaarden is a prominent researcher in the field of systems biology and molecular biology. He is known for his work on the dynamics of gene expression and cellular processes, often using innovative experimental techniques and mathematical modeling. His research typically focuses on understanding how cells process information, respond to environmental changes, and maintain stability in their functions.

Alfred Aeppli is known as a Swiss artist and painter, though specific details about his life and work may vary based on the context. He is associated with expressionism and is noted for his unique style.