Yes and No
Right so you'll be asking wtf is this ambiguous answer?
The combination of the ability Simple and Sunlight with the move Growth will boost it from +1 SpA and Atk to +4 SpA and Atk.
+4 is fundamentally different from 4x. A +4 SpA is actually 3x the original SpA - not 4x. So that's why I put Yes and No
Source: Trialled on Showdown, Experience