Step 1. The constant for this sequence is 4 since 5-1=4 and 9-5=4.
Step 2. Using this constant, we have 1+(n-1)*4 as the formula. We can check with n=1 or 1+(1-1)*4=1. With n=2, 1+(2-1)*4=5. With n=3, 1+(3-1)4=9. So it checks out.
Step 3. With n=50, then 1+(50-1)*4=197.
Step 4. ANSWER: The 50th term is 197.
I hope the above steps were helpful.