Wow! Pretty great young mathematicians. Our oldest traveled a similar path. When school didn't provide the challenges that he need in math, we were fortunate to find an ARML (American Regional Math League)Team. For those around Philadelphia, there's an excellent team at Lehigh University. Our son was involved with the team at first when he was 11 (perhaps a little young), but he got more involved at 13. It was good for him to be surrounded by older bright children as it provided an excellent challenge.
Sorry for going off topic.
