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A Rubik's Snake is a game made by Rubik Erno. It is a rod with 24 triangular prisms fixed together on 23 pivots. Each pivot can be twisted with 4 x 90 degree turns to create different shapes. I know I can find the number of forms it can take, provided that it only makes 90 degree turns at each pivot and there is no 'lack' of space (can be easily found out by taking the figures 4 twists available, and 23 pivots for each twist. $4^{23} = 70368744177664$. How would I incorporate the fact that there is limited space available, and that not all moves would be accepted? I don't mind whether they are sensitive to orientations, or not. Therefore, go for the easier option.