Kevin R. answered • 07/19/15

Tutor

New to Wyzant
Love to learn, love to help others learn.

Actually 32 terms is not unreasonable if you use excel :)

however, you may note that the answer is the sum of the digits

so given N digits the sum is (first+last) times (last-first)+1/2

the second part reduces to last / 2 when starting at 1.

1..4 1+4 *2

5*2

10

1..32 1+32 * 16

33 * 16

528