Regular sequences

1:10
 [1]  1  2  3  4  5  6  7  8  9 10
seq(from=1,to=10)
 [1]  1  2  3  4  5  6  7  8  9 10
seq(from=2,to=10,by=2)
[1]  2  4  6  8 10
seq(to=49,length.out=5,by=7)
[1] 21 28 35 42 49
rep(1:5,3)
 [1] 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
rep(1:5,each=3)
 [1] 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5