natural numbers 1 + 2 + 3 + 4 + ⋯ is a divergent series. The nth partial sum of the series is the triangular number ∑ k = 1 n k = n ( n + 1 ) 2 , {\displaystyle...

1-2-3; 1, 2, 3; or One, Two, Three may refer to: 1-2-3 (fuel station), in Norway Lotus 1-2-3, a computer spreadsheet program .123, a file extension used...

Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software (later part of IBM). It was the first killer application of the IBM PC, was hugely...

partial sums of 1 − 2 + 3 − 4 + ... are: 1, 1 − 2 = −1, 1 − 2 + 3 = 2, 1 − 2 + 3 − 4 = −2, 1 − 2 + 3 − 4 + 5 = 3, 1 − 2 + 3 − 4 + 5 − 6 = −3, ... The sequence...

3–2–1 was a British game show that was made by Yorkshire Television for ITV. It ran for ten years, from 29 July 1978 to 24 December 1988, with Ted Rogers...

3-2-1 Penguins! is an American science fiction computer-animated Christian children's television series, initially launched on November 14, 2000 as a...

is 4–2–1–3, where the midfielders are split into two defensive and one offensive player; as such, this formation can be considered a type of 4–3–3. An...

4.3.2.1. (which stands for "4 girls, 3 days, 2 cities, 1 chance") is a 2010 British crime thriller film written, produced and directed by Noel Clarke,...

3-2-1 Contact is an American science educational television show produced by the Children's Television Workshop (CTW, now known as Sesame Workshop). It...

all other integers (e.g., 1 = 1 {\displaystyle 1=1} ; 2 = 1 + 1 {\displaystyle 2=1+1} ; 3 = 1 + 1 + 1 {\displaystyle 3=1+1+1} etc.). The product of 0 numbers...