1137. N-th Tribonacci Number in F#

URL N-th Tribonacci Number - LeetCode Code https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/problems/1137/main.fsx let tribonacci (n: int) : int = let rec tribonacci' i n prev3 prev2 prev1 = if i > n then pre...