Get a seq() in R with alternating steps

Question

The seq function in R would give me a sequence from x to y with a constant step m:

seq(x, y, m)
         


        

Answer 1

First n terms of this sequence you can generate with

x = 1; m1 = 2; m2 = 4

n <- 0:10 # first 11 terms
x + ceiling(n/2)*m1 + ceiling((n-1)/2)*m2
# [1] 1  3  7  9 13 15 19 21 25 27 31