After cracking the 'sum of cubes' puzzle for 42, mathematicians discover a new solution for 3.

After years of work, there was only one number left below 100 that hadn't been proven to be the sum of three cubes. A million+ hours of worldwide supercomputer time later, even mighty 42 has fallen.

Share or comment on this article: Easy looking math equation proves tricky for people - do you know the rule to solve the sum in 30 seconds?

What seemed like a regular grade school math problem had people totally stumped on social media.

Every so often its good to exercise your brain with a math problem or two that forces you to recall principles you learned decades prior. Can you solve 5+5x5+5 without a hitch?

Both of those seem high to me, since the sum of the first 10^6 terms of the series is < 137 and the terms get smaller as they progress.