A brief code sample (in any standard language, C#, VB.Net, Java, Javascript, etc):
Create a recursive function that takes an integer as an input and writes out the console the value that follows this pattern, until 0 is reached, then exit. The pattern is simple:
For input value of 7 => -6, 5, -4, 3, -2, 1, 0
For input value of 3 => -2, 1, 0
For input value of -9 => 8, -7, 6, -5, 4, -3, 2, -1, 0