Getting output in combination form in r

Question

I have 3 variables. Hence, I will get 6 combinations. I want to produce the 2nd column in conbination form. I got the folloWing result.

P<- matrix(c (
0.427, -0.193, 0.673,
-0.193, 0.094, -0.428,
0.673, -0.428, 224.099
), c( 3,3))


G <-matrix(c(
0.238, -0.033, 0.468,
-0.033, 0.084, -0.764,
0.468, -0.764, 205.144
), c(3,3))

A<-rep(1, each=nrow(P))

df<-do.call(rbind, lapply(1:ncol(P), function(x) {
    do.call(rbind, combn(ncol(P), x, function(y) {
    data.frame(comb = paste(y, collapse = ""),
               
                B = ((solve(P)%*%G)%*%A),
               stringsAsFactors = FALSE)
    }, simplify = FALSE))
}))

>df
   comb           B
1     1 -19.7814149
2     1 -44.1515387
3     1   0.8891786
4     2 -19.7814149
5     2 -44.1515387
6     2   0.8891786
7     3 -19.7814149
8     3 -44.1515387
9     3   0.8891786
10   12 -19.7814149
11   12 -44.1515387
12   12   0.8891786
13   13 -19.7814149
14   13 -44.1515387
15   13   0.8891786
16   23 -19.7814149
17   23 -44.1515387
18   23   0.8891786
19  123 -19.7814149
20  123 -44.1515387
21  123   0.8891786

Here I got only 3 (-19.7814149,-44.1515387,0.8891786) values But I wanted 12 values.

comb     B
1   0.5574  
2   0.8936  
3   0.9154  
12  10.0772,  21.233 
13  0.2083 ,  0.9169 
23  -3.1085,  0.9061 
123 -19.7814, -44.1515, 0.8892

I can't manage this. Furthermore, I want to use these B values to calculate my desired result (GA), where my formula is

 b<-t(B)
 gain<-do.call(rbind, lapply(1:ncol(P), function(x) {
     do.call(rbind, combn(ncol(P), x, function(y) {
     data.frame(GA = abs(round(1.76*(sum(G[y,y] %*% B[y] * A[y]))/ sqrt((b[y] %*%P[y,y])%*%B[y]),2)),  
               stringsAsFactors = FALSE)
     }, simplify = FALSE))
 })) 

My final output is

comb     B                                GA
1     0.5574                              0.641
2     0.8936                              0.4822
3     0.9154                              24.1186
12    10.0772,   21.233                   3.123
13    0.2083 ,   0.9169                   24.1748
23    -3.1085,   0.9061                   24.0867
123  -19.7814,  -44.1515,  0.8892         24.9097

Is there any solution?