In general,
Note that with the first 3 cuts it is possible to divide the cake into 2, then 4 and finally 8 pieces, but it is impossible to cut each of the 8 pieces with a fourth cut, and indeed is only 15, not 16.
The first cake numbers are 1, 2, 4, 8, 15, 26, 42, 64, 93, 130, 176, 232, 299, 378, 470, 576, 697, 834, 988, 1160, 1351, 1562, 1794, 2048, 2325, 2626, 2952, 3304, 3683, 4090, 4526, 4992, 5489, 6018, 6580, 7176, 7807 more terms