could we use ":" to represent multiple matrice in a list or sequential chracter names

Hi,
 I know we can use 1:10 to represent the 1,2,3,...,10 numbers, but the
following conditions are except.
 Anybody knows how to represent the following two cases with similar  
usage
of ":"  or others? Usually, i will get several hundred names for  
them, such
as a1,a2,... or f[[1]],f[[2]],...
#Example data
a1<-array(1:12,c(2,3,2)); a2<-array(2,c(2,3,2)); a3<-array(0,c(2,3,2))

a1[1,2,1]:a3[1,2,1]
[1] 3 2 1 0
#the correct result should be 3,2,0
 So the method  of using "a1[i,j,k]:a3[i,j,k]" to represent
"c(a1[i,j,k],a2[i,j,k],a3[i,j,k])" is not correct?

##For lists with matrices as its elements
f<-list()
f[[1]]<-a1;f[[2]]<-a2;f[[3]]<-a3
f[[1]][1,2,1]:f[[3]][1,2,1]
[1] 3 2 1 0
#the correct result should be 3,2,0
  So the method  of using "f[[1]][i,j,k]:f[[3]][i,j,k]" to represent
"f[[1]][i,j,k],f[[2]][i,j,k],f[[3]][i,j,k])" is not correct?

 I noticed that the above two methods have got the same results,  
although
not correct. So i guess i have made the same errors in them. Is  
there some
method to represent them concisely?
 Any ideas about them?
 Thanks a lot.