Here are the first 5 terms of a quadratic sequence.
-4 3 16 35 60
Show that the n n\,nth term is 3n2−2n−53n^2 - 2n - 53n2−2n−5
201 exam-style questions on Eduqas GCSE Maths The Nth Term of a Quadratic Sequence. Each one has a worked solution and a mark scheme showing where the marks go.