Predictor Corrector Method; Adam Bashforth Moulton Method
Let's consider again the initial value problem 
dy/dt = t*exp(3*t) - 2*y 
y(0) = 0 
0 <= t <= 2 
A Matlab script to solve this problem that employs
the Adam Bashforth Moulton predictor-corrector method
can be downloaded here .
It uses the functions 
deriv.m  and 
exact.m .
Results (in comparison to an RK4 scheme) are
 
Let's take a look at some numbers . 
RK4 performs slightly better. 
But: For many problems, implicit schemes allow us to take larger timestep.