The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.

In A045844, a sequence is defined by a rule a(n+1) = a(n) + largest digit of a(n); a(0) = 1. As usually in such cases, direct transformation is unique, while reverse one is not. Here the number of possible "previous" terms is given for each n.