Fibonacci Series Program using Recursion in C#

According to Wikipedia the Fibonacci numbers are the numbers in the following integer sequence:

0,\;1,\;1,\;2,\;3,\;5,\;8,\;13,\;21,\;34,\;55,\;89,\;144,\; \ldots\; (sequence A000045 in OEIS)

By definition, the first two Fibonacci numbers are 0 and 1, and each subsequent number is the sum of the previous two. Some sources omit the initial 0, instead beginning the sequence with two ones.

C#.NET Tutorial, C#.NET Basics - CSharpTalk.com: Fibonacci Series Program using Recursion in C#: "Fibonacci Series Program using Recursion Code"