SOLUTION: How do I write an equation for a simple number sequence - 1,2,3,4,etc. where each time they get added together. Example would be 1 = 1 total, 2 = 3 total, 3 = 6 total, 4 = 10 tota

Algebra ->  Sequences-and-series -> SOLUTION: How do I write an equation for a simple number sequence - 1,2,3,4,etc. where each time they get added together. Example would be 1 = 1 total, 2 = 3 total, 3 = 6 total, 4 = 10 tota      Log On


   

Question 472706: How do I write an equation for a simple number sequence - 1,2,3,4,etc. where each time they get added together. Example would be 1 = 1 total, 2 = 3 total, 3 = 6 total, 4 = 10 total. I want to be able to get the total of any number. Example would be 50 = 1,275
Please help thank you!
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
You can either write it as a recursive sequence

where a_1 = 1,

or recall that the sum of the first n positive integers is n(n+1)/2, in which we get