Many palettes for the Sega Genesis are referenced from emulator screenshots, following a non-linear ramp of [0, 36, 72, 109, 145, 182, 218, 255] or the linear [0, 32, 64, 96, 128, 160, 192, 224], this palette of 512 colors uses the [0, 52, 87, 116, 144, 172, 206, 255] ramp referenced from actual hardware output data.
Here is a raw text file that can be saved as a .gpl to put them in a neat and tidy order.