Ignoring the point about the datasheet being wrong, I'm also at a loss with your schematic - unless you have some of the pins grounded.
Taking the diagram systematically:
you connect across Either end of R2 via pin 1 and pin 2,
you also need to include the parallell resistances of:
Pin 2 , through R1, R3 and R4 back to Pin 1
Pin 3 , through R1, R5 and R6 back to Pin 1
Pin 4 , through R1, R7 and R8 back to Pin 1
Pin 5 , through R1, R9 and R10 back to Pin 1
Pin 6 , through R1, R11 and R12 back to Pin 1
Pin 7 , through R1, R13 and R14 back to Pin 1
Pin 8 , through R1, R15 and R16 back to Pin 1
Now remembering 1/Rtotal = 1/R1 + 1/R2 etc ...
1/Rtotal = 1/100k + 7/300k
Rtotal = 30k ohm
So I don't know how the simulator got 56.24 ohms ?