4. The teacher is buying souvenirs for the students. There are three different types of souvenirs in the store (each type of souvenir is identical), priced at 1 yuan, 2 yuan, and 4 yuan respectively. Teacher Li plans to spend 101 yuan, and at least one of each type of souvenir must be purchased. There are $\qquad$ different purchasing plans.
4. 600.

Let the number of positive integer solutions to the equation $x_{1}+2 x_{2}+4 x_{3}=101$ be $N$. Then $N$ is the coefficient of $t^{101}$ in the expansion of
$$
\begin{aligned}
A(t)= & \left(t+t^{3}+\cdots\right)\left(t^{2}+t^{4}+\cdots\right) . \\
& \left(t^{4}+t^{8}+\cdots\right)
\end{aligned}
$$

Expanding the expression, we have:
$$
\begin{array}{l}
\text { By } A(t)=t\left(1-t^{2}\right)^{-1} t^{2}\left(1-t^{2}\right)^{-1} t^{4}\left(1-t^{4}\right)^{-1} \\
\quad=t^{7}\left(1-t^{2}\right)^{-2}\left(1-t^{4}\right)^{-1} \\
=t^{7}\left(1+t^{2}\right)^{2}\left(1-t^{4}\right)^{-3} \\
=\left(t^{7}+2 t^{9}+t^{11}\right) \sum_{k=0}^{\infty} \mathrm{C}_{k+2}^{2} t^{4 k} .
\end{array}
$$

Thus, $N=2 \mathrm{C}_{23+2}^{2}=600$.