I've not read other opinions however here is mine,
Since your husband wants to do research in Math, he is lucky, because he does not require high end instruments to do his stuff. So he basically can do research wherever and whenever he wants, meaning, he need not be in a specific place to do his research. In the mean time he can get employed in a place where he can earn money using his skills.
So while his research is done at home, he can work elsewhere till he feels that his research has matured enough to require a lot of attention. Once his work is publicized I'm sure there will be a lot of people to come forward and assist. Some of us developers use and believe in open technology as the future, hence we publish whatever we do for the benefit of the world. He can create a blog to update the world about his research.
He can use social media to find and meet people with similar interests or even conduct teaching sessions to people whom he wants to teach for a fee or for free. Example Google hangouts. Using the internet will give him better exposure than the closed walls of any university.
I help my father with his automobile business and then follow my passion at home, I don't know if any of my work is worthy of being called research but bits of it I publicize is certainly helping people who wants to learn :) .