What is the equation of the horizontal asymptote for the function $y=2(4)^{x+1}+3$ ?

Step 1 ：Analyze the behavior of the function as x approaches negative infinity: \(2(4)^{x+1}+3\)

Step 2 ：As x approaches negative infinity, the exponential term \((4)^{x+1}\) approaches 0, so the horizontal asymptote is the constant term 3.

Step 3 ：\(\boxed{y=3}\)