A triangular number is a number that is the sum of all of the natural numbers up to a certain number. When formed using regularly spaced dots, they tend to form a shape of equilateral triangle, hence the name.

21/07/2021 · A triangular number or triangle number counts objects arranged in an equilateral triangle. Triangular numbers are a type of figurate number, other examples being square numbers and cube numbers. The n th triangular number is the number of dots in the triangular arrangement with n dots on a side, and is equal to the sum of the n natural numbers from 1 to n.

Media in category "Triangular numbers". The following 59 files are in this category, out of 59 total. 153 Triangular.gif 1,576 × 1,688; 101 KB. 3eckszahl rechteck.PNG 70 × 60; 351 bytes. 3eckszahl treppe2.PNG 33 × 60; 226 bytes. 3eckszahl treppe3.PNG 42 × 60; 244 bytes. 3eckszahl treppe4.PNG 51 × 60; 287 bytes.

20/01/2013 · The th triangular number is thus one half of the th pronic number (or oblong number). A000217 Triangular numbers: a(n) = C(n+1,2) = n(n+1)/2 = 0+1+2+...+n, n ≥ 0. {0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 136, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406, 435, 465, 496, 528, , 561, 595, 630, 666, 703, 741, 780, ...}