等差系列 Fc=G(F/A,i,n-1)+G(F/A,i,n-2)+. +G(F/A,i,2)+G(F/A,i,1) -9409 -9uW-9of =60-=64Gim 88 等差系列 ( / , , 1) ( / , , 2) ( / , ,2) ( / , ,1) (1 ) 1 [ ] F G F A i n G F A i n G G F A i G F A i G i nG i i i = − + − + + + + − = − (1 ) 1 { [ ] } [ ] (1 ) 1 1 [ ] ( / , , ) (1 ) 1 n G n n G i nG i A i i i i n G G A G i n i i + − = −  + − = − = + −