[math-fun] A+B=C. Concatenate ABC

Hello Math-Fun, take 3 integers A, B and C such that A+B=C. Concatenate ABC and call the result D. Ds seq is: http://www.research.att.com/~njas/sequences/A108203 Among those Ds some can drive us back to the original A and B: D=123 --> A=1 and B=2 What about D's (D-primes) giving two possible pre- decessors: D'=22830 --> A=2 and B=28 or A=22 and B=8 Are those D's in finite quantity? Best, É.