  Biconfluent Heun (BCH) function, a confluent form of Heun function, is the
special case of Grand Confluent Hypergeometric (GCH) function: this has a
regular singularity at x=0, and an irregular singularity at infinity of rank 2.
  In this paper I apply three term recurrence formula (3TRF) [arXiv:1303.0806]
to the integral formalism of GCH function including all higher terms of A_n's
and the generating function for the GCH polynomial which makes B_n term
terminated. I show how to transform power series expansion in closed forms of
GCH equation to its integral representation analytically.
  This paper is 10th out of 10 in series "Special functions and three term
recurrence formula (3TRF)". See section 6 for all the papers in the series. The
previous paper in the series describes the power series expansion in closed
forms of GCH equation and its asymtotic behaviours. [arXiv:1303.0813]
