==== Using seq to Create a Sequence of Numbers

  $ seq -w -s " " 5 18
  05 06 07 08 09 10 11 12 13 14 15 16 17 18
  
  $ seq -w -s " " 9 3 48
  09 12 15 18 21 24 27 30 33 36 39 42 45 48

-w adds zero padding

-s replaces the new line with a space

You can set the interval as shown with the "48" above.