When I enter combinations(4,0.5) on the MathJS.org, I get a return value of 1 which may be incorrect. In my application, I am also getting the same result returned from the MathJS.eval() function.

I get an Error message when I enter the same on 2 different TI calculators that I have, as well as on another calculator emulator.

Is there an extra setting (parameter) that I need to pass into this function?