[seqfan] Proposed fix of A019989, see also A287385.

[Brad Klee]

Hi Seqfans,

Careful analysis of Gosper's abcABC1 algorithm,
including comparison with relatively easier cases,
suggests a simplified, intelligible, better definition:

https://oeis.org/draft/A019989

If this is acceptable, okay, but I think the better
edit is to cross reference A287385. This is a
really nice, detailed, helpful entry by Clark
Kimberling.

Nice work Clark!

Cheers,

Brad