SL7 blocks

Block Sizes in Compact Inner Class:
         PGL(7,R)
SU(7)    1
SU(6,1)  28
SU(5,2)  231
SU(4,3)  665 

Block Sizes in Split Inner Class:
         PU(7)  PU(6,1)  PU(5,2)  PU(4,3)
SL(7,R)  1      28       231      665