The range will be the set of values taken on by the function [tex]K(n)[/tex] for each member of the domain set [tex]D[/tex].
These values are
[tex]K(-2)=2\times(-2)^2=8[/tex]
[tex]K(1)=2\times1^2=2[/tex]
[tex]K(3)=2\times3^2=18[/tex]
So the range is the set [tex]R=\{2,8,18\}[/tex].
