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

[JMBaillard]

Hello Gerson,

thank you for the link, I didn't know this forrmula !
Here is another HP41-version:

01 LBL "LN2"
02 CLX
03 STO 00
04 SIGN
05 STO 01
06 LBL 01
07 RCL 01
08 9
09 *
10 STO 01
11 RCL 00
12 1
13 +
14 STO 00
15 ST+ X
16 LASTX
17 +
18 *
19 1/X
20 +
21 X#Y?
22 GTO 01
23 ST+ X
24 3
25 /
26 END

(37 bytes)

The HP41 returns 0.6931471807 in 5.1 seconds
and free42 gives 0,693147180559945309417232121458174

Best regards,
JM.