Sequences and nth term of triangular sequence

Material suitable for a complete lesson in sequences are provided in two worksheets. One deals with a differentiated lesson and the other, the more involved one, is to find the nth term of a triangular sequence.

The steps arriving at the nth term of the triangular sequence are given, but the pupils are expected to answer as to why each step is true, until one arrives at the last step.

Because of the inductive nature of the process, it is good practice to check if the generalised expression of the sequence works for some other situations of the sequence number.