利用者:Morley41Wiki/みかん製

${\begin{aligned}\pi ={\cfrac {4}{1+{\cfrac {1^{2}}{2+{\cfrac {3^{2}}{2+{\cfrac {5^{2}}{2+{\cfrac {7^{2}}{2+{\cfrac {9^{2}}{\ddots \,}}}}}}}}}}}}\end{aligned}}$