Posted by Paisley on .
Help me solve this input output table?
1 1
2 3
3 6
4 10
5 15
6 21
So what equation should I do to get from the number in the first column to the number in the second column?

Math 
Reiny,
I usually "play aroung" with the y values, I found this ....
suppose we double all y values
1 2 = 1x2
2 6 = 2x3
3 12 = 3x4
4 20 = 4x5
5 30 = 5x6
6 42 = 6x7
...
n > n(n+1)
Did you see the pattern ?
but remember we multiplied by 2
so, .....
y = x(x+1)/2