a(1) = 1. For n >= 2, a(n) is the number whose base a(n-1) + 1 digit values, written in base 10, are the terms from a(1) through a(n-1).

A352333

a(1) = 1. For n >= 2, a(n) is the number whose base a(n-1) + 1 digit values, written in base 10, are the terms from a(1) through a(n-1).