Elegant indexing up to end of vector/matrix

Is it possible in R to say - I want all indices from position i to the end of vector/matrix? Say I want a submatrix from 3rd column onwards. I currently only know this way:

A = matrix(rep(1:8, each = 5), nrow = 5) # just generate some example matrix...

A[,3:ncol(A)] # get submatrix from 3rd column onwards

But do I really need to write ncol(A)? Isn't there any elegant way how to say "from the 3rd column onwards"? Something like A[,3:]? (or A[,3:...])?