This is strictly NOT a A.P. This is called "Sequence of trianangular numbers", and can be summed up using the following formula: n[n +1]*[n + 2] / 6. So, the first 10 terms will sum up to:[10*11*12]/6=220.
This is strictly NOT a A.P. This is called "Sequence of trianangular numbers", and can be summed up using the following formula: n[n +1]*[n + 2] / 6. So, the first 10 terms will sum up to:[10*11*12]/6=220.