Create Combinations in R by Groups

Question

I want to create a list for my classroom of every possible group of 4 students. If I have 20 students, how I can I create this, by group, in R where my rows are each combination

Answer 1

This code below gives all unique combinations for 4 selected from 20 without duplicates.

x <- c(1:20)
combinations <- data.frame(t(combn(x, 4)))