(phixonline)-->
function fibonacci(integer n) -- iterative, works for -ve numbers
atom a=0, b=1
if n=0 then return 0 end if
if abs(n)>=79 then ?9/0 end if -- inaccuracies creep in above 78
for i=1 to abs(n)-1 do
{a,b} = {b,a+b}
end for
if n<0 and remainder(n,2)=0 then return -b end if
return b
end function
for i=0 to 28 do
if i then puts(1,", ") end if
printf(1,"%d", fibonacci(i))
end for
puts(1,"\n")