Tripartite Palindromic Partition of Integer (HP 50g) Challenge

[2old2randr]

I haven't been able to construct such a number.

What is happening here is that numbers of the form 103... with an even number of digits can be handled by either ALGO1 or ALGO4. However, if we classified them as A5/A6 and applied ALGO1, we would have an odd number of digits for p1 which causes a problem when adding back the number subtracted initially. So we pretend that the number is of type B1/B2 and apply ALGO4. The B2 path will be taken only if the last digit is '3' and this doesn't seem to be possible - at least I have not been able to find an example.