Integer If the domain is restricted to then each and every member of has one and only one corresponding member of N and by the definition of cardinal equality the two sets have equal cardinality. Integer An integer (from the Latin "integer" meaning "whole") is a number that can be written without a fractional component. For example, 21, 4, 0, and −2048 are integers, while 9.75, , and are not. The set of integers consists of zero (), the positive natural numbers (, , , …), also called "whole numbers" or "counting numbers", and their additive inverses (the negative integers, i.e.,
Integer triangle double triangular number ( + 1) and for "c" odd it is the square . It also means that the number of integer triangles with greatest side "c" exceeds the number of integer triangles with greatest side "c"−2 by "c". The sequence of the number of non-congruent integer triangles with largest side "c", starting at "c" = 1, is: The number of integer triangles (up to congruence) with given largest side "c" and integer triple ("a", "b", "c") that lie on or within a semicircle of diameter "c" is the number of integer triples such that "a" + "b" >