The following five sequence puzzles are quite nasty and hard to solve. Yet, each of them has a clear and justifiable solution.
Sequence 1:
?, ?, ?, B, B, C, ?, ?, F, ?, S, M, A, S, P, S, C, A, ...
Sequence 2:
?, ?, ?, ?, 8485, 8188, 8167, 8163, 8125, 8091, 8080, 8051, ...
Sequence 3:
..., 23, 4, 16, 33, 21, 6, 18, ?, ?, ?, ?, ...
Sequence 4:
P, M, B, ?, S, C, K, E, L, H, M, H, T, ?, R, ?, ?, ?, S, H, F, B, Y, R, S, D, B, U, M, L, ...
Sequence 5:
1, 2, 6, 7, 6, 5, 0, 6, 0, 0, 2, 2, 8, 2, 2, 9, 4, 0, 1, 4, 9, 6, 7, 0, 3, 2, 0, 5, ?, ?, ?.