- triangular number
- noun Date: 1795 a number (as 3, 6, 10, 15) representable by that many dots arranged in rows that form a triangle and that equals n(n + 1)/2 for some positive integer value of n

*New Collegiate Dictionary.
2001.*

- triangular number
- noun Date: 1795 a number (as 3, 6, 10, 15) representable by that many dots arranged in rows that form a triangle and that equals n(n + 1)/2 for some positive integer value of n

*New Collegiate Dictionary.
2001.*

**Triangular number**— The first six triangular numbers A triangular number or triangle number numbers the objects that can form an equilateral triangle, as in the diagram on the right. The nth triangle number is the number of dots in a triangle with n dots on a side;… … Wikipedia**triangular number**— noun Any integer that is the sum of n natural numbers between 1 and n. Ten is a triangular number being the sum of 1, 2, 3, and 4 … Wiktionary**triangular number**— n. number that can be arranged in the shape of a triangle having all sides equal … English contemporary dictionary**triangular number**— noun 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 … English new terms dictionary**triangular number**— … Useful english dictionary**Centered triangular number**— A centered triangular number is a centered figurate number that represents a triangle with a dot in the center and all other dots surrounding the center in successive triangular layers. The centered triangular number for n is given by the formula … Wikipedia**Square triangular number**— A square triangular number (or triangular square number) is a number which is both a triangular number and a perfect square. There are an infinite number of triangular squares, given by the formula: N k = {1 over 32} left( left( 1 + sqrt{2}… … Wikipedia**Squared triangular number**— For triangular numbers that are themselves square, see square triangular number. Visual demonstration that the square of a triangular number equals a sum of cubes. In number theory, the sum of the first n cubes is the square of the nth triangular … Wikipedia**number game**— Introduction any of various puzzles and games that involve aspects of mathematics. Mathematical recreations comprise puzzles and games that vary from naive amusements to sophisticated problems, some of which have never been solved.… … Universalium**Triangular array**— Not to be confused with Triangular matrix. The triangular array whose right hand diagonal sequence consists of Bell numbers In mathematics and computing, a triangular array of numbers, polynomials, or the like, is a doubly indexed sequence in… … Wikipedia