FIBONACCI NUMBER GENERATOR IN RN BY Mr.Z
PLEASE NOTE THAT YOU MUST COPY THE CODE INTO THE INTERPRETER TO EXECUTE IT.
THIS CODE IS KNOWN TO WORK ON THE WINDOWS-BASED INTERPRETER.
THIS IS PROBABLY TOO COMPLICATED TO RUN ON THE TI-89/TI-92+-BASED INTERPRETER.
THIS CODE IS IN THE PUBLIC DOMAIN, BUT PLEASE GIVE ME CREDIT IF YOU USE IT.

SOURCE CODE (THIS IN THIS FORM DOES NOT WORK, SEE BELOW):
0=()
A=(00)
B=(AA)
C=(BB)
D=(CC)
(
  (
    (
      (A)(
        (C)(
          (D)(
            C(((AA)D)((0)(C)D))
          )
        )
      )
      (A)
      (
        (C)
        (
          (D)
          (
            C(((AA)D)((0)(C)D))
          )
        )
      )
    )
    (0)
  )
  (0)
)

EXPANDED CODE (THIS IS WHAT GOES INTO THE INTERPRETER):
(((((()()))(((((()())(()()))((()())(()()))))((((((()())(()()))((()())(()())))(((()())(()()))((()())(()())))))((((()())(()()))((()())(()())))((((()())(()()))((((()())(()()))((()())(()())))(((()())(()()))((()())(()())))))((())((((()())(()()))((()())(()()))))((((()())(()()))((()())(()())))(((()())(()()))((()())(()())))))))))((()()))(((((()())(()()))((()())(()()))))((((((()())(()()))((()())(()())))(((()())(()()))((()())(()())))))((((()())(()()))((()())(()())))((((()())(()()))((((()())(()()))((()())(()())))(((()())(()()))((()())(()())))))((())((((()())(()()))((()())(()()))))((((()())(()()))((()())(()())))(((()())(()()))((()())(()()))))))))))(()))(()))

OUTPUT:
 1 1 2 3 5 8 13 21
(I STOPPED IT BECAUSE IT WOULD OTHERWISE RUN FOREVER)