Sequences & Series (Edexcel A-Level Mathematics): Flashcards

A list of numbers that may follow a pattern.

It's defined by a formula specific to the sequence.

The $n$-th term is denoted as $a_n$.

It's the constant difference between consecutive terms.

They have a constant ratio between consecutive terms.

It's the sum of the terms of a sequence.

$S_n = a_1 + a_2 + ... + a_n$.

$S_n = n/2 (2a + (n - 1)d)$.

$S_n = a(1 - r^n)/(1 - r)$.

The series approaches a finite sum as terms increase.