a(1) = 1; for n >= 2, a(n) is the earliest occurrence k of the next distinct pair {x(k), y(k)}, where x(k) and y(k) denote the count of zero digits in A355318(k) and A355317(k), respectively.

A355539

a(1) = 1; for n >= 2, a(n) is the earliest occurrence k of the next distinct pair {x(k), y(k)}, where x(k) and y(k) denote the count of zero digits in A355318(k) and A355317(k), respectively.