Modified pyramids

$\large \begin{array} {c c c c c c c } & 1 & & & & & & 3 \\ & 1+ 3 & & & & & & 5 + 7 \\ & 1 + 3 + 5 & & & & & & 7 + 9 + 11 \\ & 1 + 3 + 5 + 7 & & & & & & 9 + 11 + 13 + 15 \\ & 1 + 3 + 5 + 7 + 9 & & & & & & 11 + 13 + 15 + 17 + 19 \\ & \dots & & & & & & \ldots \\ & \dots & & & & & & \ldots \\ & \dots & & & & & & \ldots \\ \end{array}$

Let $a_n$ denote the sum of the first $n$ positive odd numbers and $b_n$ as the sum of the next $n$ positive odd numbers. Above shows the first 5 rows of $a_n$ and $b_n$ respectively. What is the value of

$\large b_{100} \div a_{100} ?$