Take logs of both sides:
ln(1.6491633333)=ln((1.023)^2n) where ln represents log to the base e
Now use the property ln(x^a) = a*ln(x) to get;
ln(1.6491633333)=2n*ln(1.023)
Rearrange: n = ln(1.6491633333)/(2*ln(1.023))
You can use a calculator to evaluate this.
