User blog comment:PsiCubed2/CURRENT VALUE OF PEGG/@comment-27516045-20171029235932/@comment-30754445-20171030021053

Yup.

[1,0,0,7,0 ; 38] → 100709 + log log 38 ≈ 94+7×9+0.20 = 6624.20

Once I realized that all the digits before the ";" in a PGN array run from 0 to 8, the idea of converting it to a single number base 9 was pretty obvious.