Can this implementation of Damm algorithm be optimized?

[Era Scarecrow via Digitalmars-d-learn]

On Saturday, 11 February 2017 at 20:19:51 UTC, Nestor wrote:
> Notice this is no ordinary matrix, but an Anti-Simmetric 
> QuasiGroup of order 10, and tmpdigit (called interim in the 
> algorithm) is used in each round (although the function isn't 
> recursive) together with each digit to calculate final check 
> digit.

  Yes i know, which is why i had 3 to calculate 2 inputs because 
the third is the temp/previous calculation.

  If however you were calculating a fixed number of digits a 
single table could be made and do a single lookup, assuming it 
wasn't too large to make it uncumbersome or impractical.