[seqfan] Subtracting digits, hitting zero

[Eric Angelini]

Hello SeqFans,

35,32,27,24,22,20,13,11,7,5,3,1,1,0

35 hits 0 when successively subtracting its own "digit-trail":

 a b c
35-3=32
32-5=27
27-3=24
24-2=22
22-2=20
20-7=13
13-2=11
11-4= 7
 7-2= 5
 5-2= 3
 3-2= 1
 1-0= 1
 1-1= 0 <- hit

You'll get column b reading column a digit by digit.

1) What would be the sequence S of such "hitting-zero" integers?
   I guess S starts like this:
   S = 0,1,2,3,4,5,6,7,8,9,10,19,20,22,...
2) Given an integer I, is it possible to say if I is part of S
   without computing every term of its "digit-trail"?
Best,
É.