> Stations will only appear on odd-numbered frequencies, like 88.1 MHz, 94.5 MHz, 107.3 MHz, etc. There's a technical reason for this - every FM broadcast takes up about 150 KHz of bandwidth, and spacing the broadcasts like this allows for an extra 50 KHz of wiggle room.

I believe the odd-numbered frequencies were chosen because if only even were allowed then there would be legal knock-down-drag-out fights over the round numbers.