PolskiRumia about 10 years ago [hidden] 1 + 2 + 3 + 4 + 5 + .... + n = n(n-1)/2, dear Ran. 1 Reply Copy ID Copy Link
FJH about 10 years ago [hidden] PolskiRumia said:1 + 2 + 3 + 4 + 5 + .... + n = n(n-1)/2, dear Ran.You mean n(n+1)/2. Just a finger slip, right? 1 Reply Copy ID Copy Link
