Question

stumbled upon the following problem:
a circular disk is cut into n distinct sectors each shaped like a piece of pie and all meeting at the center point of the disk.Each sector is to be painted red,green,yellow,or blue in such a way that no two adjacent sectors are painted the same color. Let Sn be the number of ways to paint the disk. Find a recurrence relation for Sk in terms of Sk-1 and Sk-2 for each integer k>=4.

Anybody can explain step by step how to solve this? any help appreciated stumbled upon the following problem:
a circular disk is cut into n distinct sectors each shaped like a piece of pie and all meeting at the center point of the disk.Each sector is to be painted red,green,yellow,or blue in such a way that no two adjacent sectors are painted the same color. Let Sn be the number of ways to paint the disk. Find a recurrence relation for Sk in terms of Sk-1 and Sk-2 for each integer k>=4.

Anybody can explain step by step how to solve this? any help appreciated @MIT 6.00 Intro Co…