Sprague-Grundy values for JG Easy version for values of n up to 30:

[1, 0, 2, 0, 1, 0, 2, 1, 2, 0, 4, 3, 3, 3, 5, 3, 3, 4, 4, 1, 3, 3, 3, 1, 6, 6, 3, 6, 6, 3]