[VA] SRC #012c - Then and Now: Sum

[PeterP]

Interesting improvement to the HP41 result:

At least on the emulator, the accuracy of ln is not good enough to calculate the number of digits in the straight forward fashion of ln(x)/ln(2). For example, for 16, this results in 3.9999999999, rather than 4.

Adding an ulp to it before taking the int fixes the problem, after which my code delivers the expected 2.086377665.