Question 6
From the natural numbers $1,2,3,\ldots$ form a sequence as follows: the first term is the odd number $1$; the next two terms are the even numbers $2,4$; the next three are the odd numbers $5,7,9$; the next four are the even numbers $10,12,14,16$; the next five are the odd numbers $17,19,21,23,25$; and so on. Determine the general term.