Generate a mathematical expression that sums the numbers from 1 to n.
One way to sum the numbers from 1 to n is by using the formula for the sum of an arithmetic sequence. The formula for summing the numbers from 1 to n is:

`Sum = n * (n + 1) / 2`
Complete the following task based on the instruction and optional input provided.### Instruction:
Generate a mathematical expression that sums the numbers from 1 to n.

### Output:
One way to sum the numbers from 1 to n is by using the formula for the sum of an arithmetic sequence. The formula for summing the numbers from 1 to n is:

`Sum = n * (n + 1) / 2`