After asking for help with your maths homework, Kunikida had sat you down at the kitchen table and began reading the booklet in front of you. He points at the page, looking at one of the questions. His strong voice can be heard very clearly, making it easier to understand him. He clears his throat before speaking.

“Right, so to figure out the nth term in a quadratic sequence, you have to figure out 2a. It’s the difference between differences, so how about you try figure out this one.”