1. The problem statement, all variables and given/known data what is the general formula for the sequence (1/1*3+1/3*6+1/6*10+1/10*15....) 2. Relevant equations i used the equation n/mn+1 but am not able to use it for this sequence 3. The attempt at a solution I found the sequence of the denominators which is (1/2)n^2+(1/2)n but am not able to find the general formula for the sum of this sequence. apparently 1/mn+! doesnt work either.