I learned FORTRAN on an IBM 1401. Our intro chemistry professor thought it was a good idea to incorporate IBM's FORTRAN programming coursework into our chemistry lab. I wasn't so good at chemistry but excelled in programming and so earned a decent chem grade. In the years that followed I used the FORTRAN for numerical analysis classes. It all led to a career in programming.
The 1401 was more of a service processor for a mainframe. You could use a 1401 to order jobs and manage card sorters and things of that nature.
The 1401 was occasionally sold as a standalone accounting machine instead of a service processor, but never as a mainframe unto itself.
It's more of a minicomputer than a mainframe. Which should say everything about its era. "Mini" meant only like, six racks of gear.