èrxiàngshìxìshù
ㄦˋ ㄒㄧㄤˋ ㄕˋ ㄒㄧˋ ㄕㄨˋ
Simplified 二项式系数
Taivo → Settings → Partner inbox → Make the link. It stays in this browser.
Keep 二項式係數 and it comes back until you know it.