Solution
= Solution
For the same uniform grid and even $n$, the <composite Simpson's rule> integrates a quadratic interpolant over each successive pair of strips:
$$
\boxed{S_n=\frac h3\left[f(x_0)+f(x_n)+4\sum_{j=1}^{n/2}f(x_{2j-1})+2\sum_{j=1}^{n/2-1}f(x_{2j})\right].}
$$
The weights are $1,4,2,4,\ldots,2,4,1$, which explains the even number of strips.