use List::Util qw[ shuffle ];

my @randUnique = shuffle map{ sprintf "1%011d", $_ } 1 .. 25e3;;

print $randUnique[ $_ ] for 1 .. 10;; ## First 10
100000016682
100000002653
100000013669
100000004625
100000009482
100000002763
100000022284
100000000048
100000015278
100000012155