Definition of triangular number in English:
Any of the series of numbers (1, 3, 6, 10, 15, etc.) obtained by continued summation of the natural numbers 1, 2, 3, 4, 5, etc.
- This triangle has an elementary use in probability and combinatorics, and both the series of triangular numbers and the Fibonacci series can be derived from it.
- The triangular numbers and the Fibonacci numbers can be found in Pascal's triangle.
- Pythagoras studied properties of numbers which would be familiar to mathematicians today, such as even and odd numbers, triangular numbers, perfect numbers etc.
Definition of triangular number in:
- British & World English dictionary