Hello from MrBillDoesMath!
Answer:
Discussion:
I stared at the numbers 19, 29, 39, 49, 59, 69,... for a second and noticed that adding 10 to any number gives the next number to the right. For example,
19 + 10 = 29
29 + 10 = 39
39 + 10 = 49
etc.....
A recursive formula would be:
a(0) = 19
a(n+1) = a(n) + 10 if n >= 0
Regards,
MrB