Recursive Fibonacci in Bash script

Question

This is my attempt:

#!/bin/bash

function fibonacci(){

first=$1
second=$2

if (( first <= second ))
then
return 1

else 

return $(fibonacci $((first-1))         


        

Answer 1

Short version, recursive

fib(){(($1<2))&&echo $1||echo $(($(fib $(($1-1)))+$(fib $(($1-2)))));}