sequences

• a sequence is a set of numbers that belong next to eachother according to a rule
• if a sequence has a last term it is finite
• if a sequence has no last term it is infinite
• a recurrence relation is one in which each successive term depends on the previous term
• first-order recurrence relation: defines a relationship between two successive terms of a sequence
• arithmetic sequence: each term is obtained by adding or subtracting a constant