A-level Mathematics/MEI/C2/Sequences and Series

Sequences and Series - Principles
A sequence is a set of numbers in a given order: ½ ⅓ ⅔ ¼

Arithmetic sequences: $$ a_n = an + b $$

Geometric sequences: $$ a_n = a r^{n-1} $$

Oscillating sequences: $$ a_n = (-1)^n $$

Periodic sequences.