Triangular Numbers

Overview

The $n$th term of the triangular numbers $(T_n{)}_{n\ge 0}$ is the sum of whole numbers ${\sum }_{k=0}^{n}k$. The first few terms are $0,1,3,6,10,15,21,28,36,45,55,\dots$

Bibliography

• Oscar Levin, Discrete Mathematics: An Open Introduction, 3rd ed., n.d., https://discrete.openmathbooks.org/pdfs/dmoi3-tablet.pdf.
• “Triangular Number,” in Wikipedia, January 13, 2024, https://en.wikipedia.org/w/index.php?title=Triangular_number&oldid=1195279122.