Function: hgmgamma
Section: hypergeometric_motives
C-Name: hgmgamma
Prototype: G
Help: hgmgamma(H): returns the gamma vector of the hypergeometric motive
 template H.
Doc:  returns the gamma vector of the hypergeometric motive
 template $H$.
 \bprog
 ? H = hgminit([5]);
 ? hgmgamma(H)
 %2 = Vecsmall([-5, 0, 0, 0, 1])
 @eprog
