Basset function | Macdonald function | modified Bessel function of the third kind

The modified bessel function of the second kind is the function K_n(x) which is one of the solutions to the modified Bessel differential equation. The modified Bessel functions of the second kind are sometimes called the Basset functions, modified Bessel functions of the third kind, or Macdonald functions (Spanier and Oldham 1987, p. 499; Samko et al. 1993, p. 20). The modified Bessel function of the second kind is implemented in the Wolfram Language as BesselK[nu, z].

Bessel function of the second kind | continued fraction constants | modified Bessel function of the first kind

BesselK

Friedrich Wilhelm Bessel