Board Thread:Wiki discussions and announcements/@comment-26053782-20150129202217/@comment-3250799-20150130030959

http://www.wolframalpha.com/input/?i=%2890%2B250*1.05%29%2BSum%5B0.06%5Ek+%2890+%2B+250+1.05%29+1.05%2C+%7Bk%2C+1%2C+Infinity%7D%5D