if the tolerance can only accept gamma function, rational function

How to convert Kummer expression into other simple formula?

i have calculated a generating function, but the actual answer is much simpler than this

Gen := {p(z) = exp(-I*z/sqrt(c))*KummerM(-(-(1/2)*sqrt(c)*beta+(1/2*I)*beta*c+I*(-1/2+c)*x)/sqrt(c),
beta,
(2*I)*z/sqrt(c))*(-KummerU(-(1/2)*(-sqrt(c)*beta+I*beta*c-I*x+(2*I)*c*x)/sqrt(c),
beta, 0)*_C1+1)+exp(-I*z/sqrt(c))*KummerU(-(-(1/2...

rsolve({c*(n+beta)*P(n+1)/(-1+c)+(c*(x+beta)/(1-c)-x)*P(n)+n*P(n-1)/(-1+c)=0,P(0)=1}, P(n));
return rsolve({c*(n+beta)*P(n+1)/(-1+c)+(c*(x+beta)/(1-c)-x)*P(n)+n*P(n-1)/(-1+c)=0,P(0)=1}, P(n));

Any other method besides rsolve to solve genfun?

i discover it can solve variable coefficient and n coefficient too.

but sometimes n*P(n+1) make it can not solve, i have to remove n to P(n+1)

any paper describing the mechanism of rsolve, where it store the maple code of rsolve in maple 15?

with(SumTools):
rsolve({c*(n+beta)*P(n+1)/(-1+c)+(c*(x+beta)/(1-c)-x)*P(n)+n*P(n-1)/(-1+c)=0,P(0)=1}, P, 'genfunc'(z));

all given, but rsolve said invalid options, why P not in terms of other variables?

http://www-igm.univ-mlv.fr/~gauthier/HYPERG.html

> Read("D:/Feb2012/HYPERG.mw"); with(HYPERG);
Error, invalid input: with expects its 1st argument, pname, to be of type {`module`, package}, but received HYPERG

HYPERGLIB := "D:/Feb2012/";
libname := libname, HYPERGLIB:

both methods above.

after typing PolyRecSol(H...

no result in Maple 15, just return similar command, no equation return.