Let
be a Bessel function of the first kind,
a Bessel function of the second kind,
and
a modified Bessel function of
the first kind. Also let
and
. Then the Dixon-Ferrar formula
(Magnus and Oberhettinger 1948, p. 45; Iyanaga and Kawada 1980, p. 1476; Gradshteyn and Ryzhik 2000, p. 657).
This is a special case of the more general formula
(Magnus and Oberhettinger 1948, p. 44; Gradshteyn and Ryzhik 2000, p. 703) for
and
.