inPvec <-1
 for (x in 1:12){
 if(x == 1) inPvec <- 1
 else {
 inPvec <- inPvec * x
 }
 cat(x, "!:", inPvec, "\n")
 }

## 1 !: 1 
## 2 !: 2 
## 3 !: 6 
## 4 !: 24 
## 5 !: 120 
## 6 !: 720 
## 7 !: 5040 
## 8 !: 40320 
## 9 !: 362880 
## 10 !: 3628800 
## 11 !: 39916800 
## 12 !: 479001600