A chess board is 8x8 and

2^8 - 1
-------
 8 - 1
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is 255/7 = 36.4285714285... Take the first 8 digits and write the letters a..h beside them to get

a3, b6, c4, d2, e8, f5, g7, h1
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this is a solution to the problem.

Update: added "explanation".