Systemic Sampling

I want to take a randomly selected number between 1 and 50, let’s call it h_1 and I want to generate the next 9 numbers in the sequence by adding 7 each time. I also want to keep the sequence numbers between 1 and 50 (so if one of the numbers in the sequence goes above 50 I need it to go back to 1, 2, etc). I want those 10 numbers to go in a list, let’s call that A_1.

What I have right now is this:
A_1= (mod(h_1+(r-1)7,50))[1…r]
When I made a table for A_1 it gives me the first number and than everything else is undefined. Any ideas?

How’s this?

Thank you very much, that works great!