A puzzle about a series or collection of symbols, elements, or other objects, whose chosen ordering obeys a specific logical rule, which is usually to be determined.
A sequence is a series or collection of symbols, elements, or other objects, whose chosen ordering obeys a specific logical rule. In sequence puzzles, the aim for the solver is usually to deduce or discover the rule behind this ordering, and/or supply the next - or missing - member(s) of the sequence.
For sequences consisting specifically of numbers, letters, or words, use the appropriate tags number-sequence, letter-sequence, or word-sequence as well.