How to create a list, a hash or a sequence

Code

<#assign myList = [ "red", "blue", "green" ]>
${myList[0]} <!-- "red" --> 

<#assign myHash = { "aa": "01", "bb": "02", "cc": "03" }>
${myHash.aa} <!-- "01" --> 

<#assign myHashSequence = { "aa": [ {"art": "desk"}, {"art": "chair"} ] }>
${myHashSequence.aa[1].art} <!-- "chair" --> 

<#assign mySequence = [
    { "name": "whale", "weight": 2000 },
    { "name": "Barbara", "weight": 53 },
    { "name": "zeppelin", "weight": -200 },
    { "name": "aardvark", "weight": 30 },
    { "name": "beetroot", "weight": 0.3 }
]>
${mySequence[1].name} <!-- "Barbara" -->