We introduce a novel integer sequence defined by repeated rotation-subtraction. For any positive integer a₀, we define aᵢ₊₁ = |aᵢ − rot(dᵢ−1)(aᵢ)| where dᵢ is the number of digits of aᵢ and rot(dᵢ−1) denotes cyclic rotation of digits by dᵢ−1 positions and there is one mistake in the pdf i claimed 7 digit no.s always reach zero it is wrong some no.s can enter into a loop also
Venkata Harsha Vardhan Gudimella (Sat,) studied this question.