AKON: Steps Up as Baby Daddy

You don't see this every day -- Akon has filed legal papers asking to take responsibility for two kids he fathered in 2008 and 2009.

The motion, filed in Georgia, asks for joint custody of the children, that they keep his last name -- Thiam -- and that the court take all of his income into account in determining child support. He also asks that in the event of his death, the kids be able to inherit from him.

A source tells TMZ, "Akon has been a father to the boys since they were born, and this is just a necessary step to make sure he is legally recognized as such."