# [PowerShell], 37 bytes

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    2*($args|sort -u).count-eq$args.count

[Try it online!][TIO-jxuddqyp]

[PowerShell]: https://github.com/TryItOnline/TioSetup/wiki/Powershell
[TIO-jxuddqyp]: https://tio.run/##fU9BbsIwELz7FZFI66TdoNhxaufQKy/gXiFkKFVEICECifD2dLwBcUOWZ3dm1@vZQ3P2bffr63qMN9/XUX8k8arddkPXtKco69P5uun3p8wfWZ7YeBNitmx7LxJLqqCKNKkcYEJgyVCVkkgUxIIYmeZo4Au4p3fGZY1ezZ2OtKbSKleRqfSDOHJMp3wqY046vF3le7yJ5Gf8k/01u72M5LDzl5uQUswWq7qD1S@YMhTQhht@weDHCbTEMEMBEYNgLRUKAsBhMYsUFp6L6cm3CYP5QYlVivyVo/Ef "PowerShell – Try It Online"

Makes a sorted list of unique numbers and compares double its size to the original list. Only Noah lists will fit the bill.