I found this website that claims that Hubertus is a the patron saint of mathematicians, among a whole hosts of other things. I can't seem to find any other information on this aspect of him. Does anyone know how this came about?
How did Hubertus became patron saint of mathematicians?
Rarely does Rome name a patron saint for a particular trade or group of individuals united in some endeavour of some sort. Once in a while the pope will name a particular saint a patron saint, especially if it involves more modern subject matters.
Thus Pope St. John Paul II name St. Thomas More the patron saint of statesmen and politicians in the year 2000.
St. Isidore of Seville was named the the patron saint of the Internet Pope John Paul the Great.
As Grateful Disciple explained it in his answer to this question (What are the criteria for a saint becoming the Patron saint of something in the Catholic Church?)
A 2012 parish article Patron Saints by RCIA director Tom Schenk provides a short summary (emphasis mine):
The earliest records show that people and churches were named after apostles and martyrs as early as the fourth century. Recently, the popes have named patron saints but patrons can be chosen by other individuals or groups as well. Patron saints are often chosen today because an interest, talent, or event in their lives overlaps with the special area.
Angels can also be named as patron saints. A patron saint can help us when we follow the example of that saint’s life and when we ask for that saint’s intercessory prayers to God. For example, Francis of Assisi loved nature and so he is patron of ecologists.
Francis de Sales was a writer and so he is patron of journalists and writers. Clare of Assisi was named patron of television because one Christmas when she was too ill to leave her bed she saw and heard Christmas Mass—even though it was taking place miles away.
Thus we see that individuals and even groups can name their own patron saints. Many times there is an historical reason certain groups claim someone as a patron saint, like fishermen taking the Apostle St. Peter as their patron saint because he was a fisherman. But this is not always the case.
In regards to St. Hubertus of Liege there seems to be no historical link in his life as to why he was chosen as a patron saint of mathematicians other the fact that St. Hubert was extremely popular at one time and some mathematicians decided to claim him as their patron saint and it stuck.