彩洗系列

$颜色\ dfrac{\{品红}{1 ^ 2}}{\颜色{# 302 b94} {1}} + \ dfrac{\颜色{品红}{5 ^ 2}}{\颜色{# 302 b94} {11}} + \ dfrac{\颜色{品红}{9 ^ 2}}{{# 302 b94} \颜色{(11)^ 2}}+ \ dfrac{\颜色{品红}{13 ^ 2}}{{# 302 b94} \颜色{(11)^ 3}}+ \ dfrac{\颜色{品红}{17 ^ 2}}{{# 302 b94} \颜色{(11)^ 4}}+ \ cdots = \ ?$