%I #14 Jan 03 2019 13:26:48

%S 2102222,11102222,12022222,120022222,202022221,1200022222,2002022221,

%T 2020022221,12000022222,20200022221,202000022221

%N Complete list of numbers that take three steps to collapse to a single digit in base 3 (written in base 3).

%H Steve Butler, R. L. Graham, Richard Stong, <a href="http://www.math.ucsd.edu/~ronspubs/mis_17_bases.pdf">Collapsing numbers in bases 2, 3, and beyond</a>, in Gathering for Gardner 10, 2014.

%Y Cf. A253057.

%K nonn,fini,full

%O 1,1

%A _N. J. A. Sloane_, Jan 13 2015