N-th Tribonacci Number LeetCode solution in Python

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class Solution:
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    def tribonacci(self, n: int, q={}) -> int:
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        if n < 3:
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            q[0] = 0  # Initialize first 3 values
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            q[1] = 1
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            q[2] = 1
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        if n not in q:  # Have faith that last 3 calls will give the answer :)
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            q[n] = (
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                self.tribonacci(n - 1, q)
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                + self.tribonacci(n - 2, q)
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                + self.tribonacci(n - 3, q)
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            )
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        return q[n]