[1] has "no value" = ""


 
array(13) {
  [0]=>
  string(0) ""
  [1]=>
  string(1) "1"
  [2]=>
  string(1) "2"
  [3]=>
  string(1) "3"
  [4]=>
  string(1) "4"
  [5]=>
  string(1) "5"
  [6]=>
  string(1) "6"
  [7]=>
  string(1) "8"
  [8]=>
  string(1) "9"
  [9]=>
  string(2) "10"
  [10]=>
  string(2) "11"
  [11]=>
  string(2) "12"
  [12]=>
  string(2) "13"
}