Judging by your example, I believe you mean b repeated a times. Not a times b.
Yes there is a command for that.
repmat(b,1,a)
The first number is what is to be repeated. The second number is how many rows to be repeated across. The third number is how many columns to be repeated across.
Edit : This actually doesn't combine them into one number but puts it into a matrix. Combine after repeating? Not sure how to do in one step. Maybe another approach out there. If you don't mind turning the result into a string, combining them, then turning it to a number, that's what I would do.
