Write a recursive definition for the sequence 11,8,5,2 ...

The series 11,8,5,2 ... is an arithmetic progression with an arithmetic difference of - 3. This is true because 11-3 is 8, 8 minus 3 is 5 and 5-3 is 2 and so on ... The formula of this arithmetic progression is equal to an = 11 - 3 (n-1) where an is the number at nth term. This is simplified to an = - 3n + 4.