Let a function f : N N be defined by
f(n) = \left[ {\matrix{
{2n,} & {n = 2,4,6,8,......} \cr
{n - 1,} & {n = 3,7,11,15,......} \cr
{{{n + 1} \over 2},} & {n = 1,5,9,13,......} \cr
} } \right.
then, f is
JEE Main 2022 · 28 Jun, Morning shift · Q3805