collatz_senary.sed

s/^/e/
:loop
s/e0/0e/;t loop
s/e1/0o/;t loop
s/e2/1e/;t loop
s/e3/1o/;t loop
s/e4/2e/;t loop
s/e5/2o/;t loop
s/o0/3e/;t loop
s/o1/3o/;t loop
s/o2/4e/;t loop
s/o3/4o/;t loop
s/o4/5e/;t loop
s/o5/5o/;t loop
s/^0//
s/e$//
s/o$/4/