#JavaScript (ES6), <s>33</s> 28 bytes

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    n=>eval(1+("*"+n).repeat(n))

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##Try It
Late night golfing on my phone again; if the below doesn't work, feel free to fix it.

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    f=
    n=>eval(1+("*"+n).repeat(n))
    o.innerText=f(i.value=3)
    i.oninput=_=>o.innerText=f(+i.value)

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    <input id=i type=number><pre id=o>

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##33 byte solution
    n=>eval(Array(n).fill(n).join`*`)