There are main 3 ways for randomizing, a sequence (random), an option (randomly) and an action (randomize)

The sequence 'random'

HTML RESULT 
{sequence random, rows=25, minimal=10, maximal=50         } {$sequence} {/sequence}
23 27 36 20 41 45 24 38 42 16 38 33 38 23 15 13 34 38 43 27 50 30 22 26 49
{sequence random, rows=25, minimal=10, maximal=50, unique } {$sequence} {/sequence}
32 49 46 14 38 16 19 23 37 40 13 42 31 21 29 30 27 28 22 20 12 50 44 15 34

The sequence option 'randomly'

Here the loop index is randomly set before the sequence is executed.

HTML RESULT 
{sequence power=2, rows=10, randomly, from=8, to=16} {$sequence} {/sequence}
512 16384 4096 4096 16384 8192 4096 65536 1024
{sequence prime,   rows=10, randomly, to=1000      } {$sequence} {/sequence}
263 743 181 41 443 241 479 811 919 311

The sequence action 'randomize'

HTML RESULT 
{sequence from=10, to=20, push='mySeq'}
{mySeq}             {$sequence} {/mySeq}
10 11 12 13 14 15 16 17 18 19 20
{mySeq randomize  } {$sequence} {/mySeq}
18 16 19 20 12 17 10 15 13 11 14
{mySeq randomize=5} {$sequence} {/mySeq}
16 15 10 13 12