循环级数

Recur \Re*cur"\ (r?*k?r"), v. i. [imp. & p. p. {Recurred}
(-k?rd"); p. pr. & vb. n. {Recurring}.] [L. recurrere; pref.
re- re- + currere to run. See {Current}.]
1. To come back; to return again or repeatedly; to come again
to mind.

When any word has been used to signify an idea, the
old idea will recur in the mind when the word is
heard. --I. Watts.

2. To occur at a stated interval, or according to some
regular rule; as, the fever will recur to-night.

3. To resort; to have recourse; to go for help.

If, to avoid succession in eternal existence, they
recur to the ``punctum stans'' of the schools, they
will thereby very little help us to a more positive
idea of infinite duration. --Locke.

{Recurring decimal} (Math.), a circulating decimal. See under
{Decimal}.

{Recurring series} (Math.), an algebraic series in which the
coefficients of the several terms can be expressed by
means of certain preceding coefficients and constants in
one uniform manner.