How do I find a formula for #s_n# for the sequence -2, 1, 6, 13, 22,...?
1 Answer
Jan 28, 2015
I would suggest you to find the formula for
The idea is that the differences have been increasing by 2.
-2 to 1 is +3
1 to 6 is +5
6 to 13 is +7
So
One can guess that
For
Good luck!