The sequence you've provided seems to follow a pattern of two alternating sequences.
The first series (the odd-indexed terms) is: 1, 2, 3, 4, 5, 6, 5
The second series (the even-indexed terms) is: 20, 30, 40, 50, 60, 60
If we continue the pattern, the next number for the odd sequence (after 5) would be 6 again. Hence, the next term in this series will be 70, which comes from continuing the even series where each term increases by 10. So, the next term could be written as:
6, 70
This suggests that the next complete term in your original structure would adhere as:
6, 70