Find or Investigate the Function as Requested $4 n$ B) $4 ^ { \mathrm { n } }$

Multiple Choice

Find or investigate the function as requested.
-Find a function f(n) whose domain is the set of natural numbers and the output produces the terms of the sequence 4, 16, 64, 256, . . .

A) $4 n$
B) $4 ^ { \mathrm { n } }$
C) $\mathrm { n } ^ { 4 }$
D) There is no such function.