[librasteve]

yes guess (thanks!)

well - try it on your own machine - code as noted above (with reflection of the input value)

then,

  > time raku fibo.raku 10 20 30 40
  
  10 55
  20 6765
  30 832040
  40 102334155
  raku fibo.raku 10 20 30 40  0.11s user 0.01s system 116% cpu 0.133 total

Caveat - this is absolutely not purporting to be a benchmark, it was as big a (pleasant and counterintuitive) surprise to me as to anyone.