Bessel function K(n,z) (McDonald's function)

is the solution of the modified Bessel equation which is singular at z=0 and has the following behavior at positive infinity:
It admits the following integral representation:
n-index, z-argument 
 MathMate syntax:            K(n,z) 
 Domain:                     n an integer, z positive real
Note: If the index is given as a non-integer number MathMate rounds it towards negative infinity.

See also: