# §13.6 Relations to Other Functions

## §13.6(ii) Incomplete Gamma Functions

For the notation see §§6.2(i), 7.2(i), 8.2(i), and 8.19(i). When is an integer or is a positive integer the Kummer functions can be expressed as incomplete gamma functions (or generalized exponential integrals). For example,

Special cases are the error functions

13.6.7

## §13.6(iii) Modified Bessel Functions

When the Kummer functions can be expressed as modified Bessel functions. For the notation see §§10.25(ii) and 9.2(i).

## §13.6(v) Orthogonal Polynomials

Special cases of §13.6(iv) are as follows. For the notation see §§18.3, 18.19.

13.6.17
13.6.18

## §13.6(vi) Generalized Hypergeometric Functions

For the definition of when neither nor is a nonpositive integer see §16.5.