This is a security problem for Project Euler and should have been disclosed to them as such. Dropping what amounts to a zero-day on their submission form is not acting in good faith.<p>The right way to go about this would have been to break the captcha, submit the problems, and then email them a polite writeup. Claim the glory <i>after</i> they fix it.
nice simple approach!<p>And despite the previous commenter I don't see a problem with publishing a neat solution to a fairly cursory attempt to prevent automated submissions. If they care enough they can fix it, but the rather simplistic nature of their capcha implies they don't care much. <i>shrug</i>
Heh! I implemented this a few years ago as part of a command line client for submitting solutions.<p><a href="https://bitbucket.org/kevinburke/euler" rel="nofollow">https://bitbucket.org/kevinburke/euler</a>