R, how to create a sequence of numbers with gaps in it? [duplicate]

Question

How to efficiently generate the following sequence of numbers in R? 4, 5, 10, 11, 16, 17, ..., 178, 179

Answer 1

One way is to think of it as the union of two sequences.

sort(c(seq(4,178,6), seq(5,179,6)))
 [1]   4   5  10  11  16  17  22  23  28  29  34  35  40  41  46  47  52  53  58
[20]  59  64  65  70  71  76  77  82  83  88  89  94  95 100 101 106 107 112 113
[39] 118 119 124 125 130 131 136 137 142 143 148 149 154 155 160 161 166 167 172
[58] 173 178 179