名詞 recursion:

1. (mathematics) an expression such that each term is generated by repeating a particular mathematical operation

re.cur.sion

n.Mathematics （名詞）【數(shù)學】
An expression, such as a polynomial, each term of which is determined by application of a formula to preceding terms.
遞推：多項式等一種表達式，每一項由前一項使用的公式來決定
A formula that generates the successive terms of a recursion.
遞推方程：產(chǎn)生連續(xù)遞推項的方程式

來源：
Late Latin recursiô recursiôn- [a running back]
后期拉丁語 recursiô recursiôn- [一個回流]
from Latin recursus [past participle of] recurrere [to run back] * see recur
源自 拉丁語 recursus [] recurrere的過去分詞 [流回] *參見 recur

【引伸】
recur.sive
adj.（形容詞）