nfib = (n) { if (n < 2) 1; else nfib(n-1) + nfib(n-2) + 1; };

then  = cputime();
calls = nfib(32);
now   = cputime();
secs  = now - then;

print(calls, " calls in ",
      secs, " seconds = ",
      round(calls / secs), " calls/sec\n");