To solve this, compute strange(0) then strange(1) then strange(2) then strange(3) and finally strange(4).
strange(0) = 2 strange(1) = strange(0) + 3 = 5 strange(2) = strange(1) + 3 = 8 strange(3) = strange(2) + 3 = 11 strange(4) = strange(3) + 3 = 14