Binomial coefficients and Pascal's triangle
Textbooks
Kenneth H. Rosen, "Discrete Mathematics and Its Applications," 8th Edition, McGraw Hill Education, 2018. (Chapter 6: Counting and Binomial Theorem)
Ralph P. Grimaldi, "Discrete and Combinatorial Mathematics: An Applied Introduction," 5th Edition, Pearson, 2003. (Chapter 1.3: Combinatinos: The Binomial Theorem
Online Resources
Khan Academy: "Pascal's Triangle and Binomial Expansion"
Brilliant.org: "Pascal's Triangle"
GeeksforGeeks:
NPTEL Courses:
MIT OpenCourseWare: