An oblong number is one that gives the number of dots in a rectangular grid having one more row than it has columns. The first few oblong numbers are shown below.

(A) Using $\displaystyle {n}$ as your variable, find a formula for $\displaystyle {O}_{{n}},$ the nth oblong number. Enter it below:

Answer: $\displaystyle {O}_{{n}}=$ (Don't forget to use $\displaystyle {n}$ as your variable.)
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(B) Find the following oblong numbers:

(i) $\displaystyle {O}_{{49}}=$

(ii) $\displaystyle {O}_{{33}}=$

(iii) $\displaystyle {O}_{{12}}=$