Python, 53 bytes ÷ 2 = 26.5

lambda n:[n-i%-~n%(i//n-~n)for i in range(n*~n//2,0)]

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This uses ranges like many other answers here but groups them in pairs (longest,shortest);(2nd longest,2nd shortest) etc. That way we can use a closed form expression inside a flat loop.

Python, 53 bytes ÷ 2 = 26.5

lambda n:[n-i%-~n%(i//n-~n)for i in range(n*~n//2,0)]

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Python 2 version, 51 bytes ÷ 2 = 25.5

lambda n:[n-i%-~n%(i/n-~n)for i in range(n*~n/2,0)]

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This uses ranges like many other answers here but groups them in pairs (longest,shortest);(2nd longest,2nd shortest) etc. That way we can use a closed form expression inside a flat loop.