Takes a value inputed and returns a single number like W(number inputed) = blank

make a recursive function in PYTHON called sequence that takes a postive number and returns the value of Wn Sn rule is Wn-1+2W1-2+Wn-3 another way of saying it if the last three terms of the sequence you've found are a b c then the next term in the sequence is a+b+b+c. so the first number in the sequence would be W. 0 Wi=1 W2= 2 then the number in the sequence are 0, 1, 2, 4, 9, 19, 41, 88, 189, 406 .... =