Find the missing number?

The missing number is $\boxed{1023}$.

The numbers in the sequence are the sum of the squares of the first $n$ natural numbers, where $n$ is the position of the number in the sequence. For example, the first number in the sequence is $1$, which is the square of $1$. The second number in the sequence is $4$, which is the square of $2$. The third number in the sequence is $9$, which is the square of $3$. And so on.

The tenth number in the sequence is the sum of the squares of the first $10$ natural numbers, which is $1023$.

Here is a table of the first few numbers in the sequence:

Number | Sum of the squares of the first $n$ natural numbers
——- | ——–
1 | $1$
2 | $4$
3 | $9$
4 | $16$
5 | $25$
6 | $36$
7 | $49$
8 | $64$
9 | $81$
10 | $1023$