Natural logarithm of 2 [HP-15C/HP-42S/Free42 & others]

[Albert Chan]

Inspired by Valentin Albillo post on estimating Pi using random numbers.
And, the proof for it: https://math.stackexchange.com/questions...379#885379

LN(2) = 2 * probability of integer part of RND/RND is odd

10 INPUT K @ N=0 @ FOR I=1 TO K @ N=N+MOD(IP(RND/RND),2) @ NEXT I @ DISP 2*N/K @ GOTO 10

> RANDOMIZE 1
> RUN
? 1E3     → .68
? 1E3     → .756
? 1E4     → .6806
? 1E4     → .6938