1
These two separate sequences use the same rule. This gives them the potential to extend much further. Still, I think they are longer than half the similar sequences based on this rule.
2, 1, 8, 5, 2, 5, 8, 6, 7, 9, 7, 7, 0
3, 1, 5, 3, 9, 2, 4, 3, 9, 7, 3, 1, 0
They are purely math...