In the infinite series 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5... each positive integer k appears k times in consecutive order.
Write a formula for the sum of the first n terms of the series.
(In reply to
re(2): A formula by Charlie)
I believe I derived an explicit formula for the sum (without summation) in my solution.

Posted by Dennis
on 20070515 07:57:21 