Really fun, but it seems like it provides JS input even if you use python. This causes all of the input cases to be marked as incorrect. For the Arith Geo question, here was my code: https://gist.github.com/1809940 and here was the result: https://gist.github.com/1809944 . So for example it said 'new Array(1,2,3,4)' yielded incorrect output. But I tried running [1,2,3,4] and it worked fine.

I know I selected python because it let me test my code by running it both before and after I submitted.

Anyway it's still really fun - keep up the good work!