[uninverted]

I wonder what a language with a three character Fibonacci sequence would be like. You'd probably need Unicode, if the language wasn't specifically designed for the Fibonacci sequence.

[mahmud]

A "language" that has fibonacci builtin can do it 2 characters. fx. where f is the name of the fibonacci function and x is a single digit number.

A fibonacci DSL could do it in 1; if all input is expected to be an integral value and the machine only computes fibonacci values, then typing a single digit number would have the intended consequence:

   (loop
     (print (fib (parse-integer (read)))))

[blasdel]

Someone clearly needs to extend HQN+ with another primitive -- http://www.cliff.biffle.org/esoterica/hq9plus.html

[tesseract]

http://www.dyalog.com/dfnsdws/n_fibonacci.htm