Fictional Fnargs are either red or blue and have 2, 3 or 4 heads. A group of six Fnargs consisting of one of each possible form is made to line up such that no immediate neighbours are the same colour nor have the same number of heads. How many ways are there of lining them up from left to right?
Last week's solution:
The distance is roughly 8 x 1022 miles
Source: UKMT