Function: hgmcoef
Section: hypergeometric_motives
C-Name: hgmcoef
Prototype: GGG
Help: hgmcoef(H,t,n): (H,t) being a hypergeometric motive, returns the
 n-th coefficient of its L-function.
Doc: $(H,t)$ being a hypergeometric motive, returns the
 $n$-th coefficient of its $L$-function. This is not implemented for wild
 primes $p$ and will raise an exception if such a $p$ divides~$n$.
