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");

numbers = 8192; // 1028 primes
repeats = 200;

count = 0;

then  = cputime();

evals = evaluations();

for (n = 0;  n < repeats;  n = n + 1) {
    print("\r", n, "/", repeats);
    sieve = [];
    count = 0;
    for (i in numbers) sieve.push(nil);
    for (i = 2; i < numbers;  i = i + 1) {
        if (!sieve[i]) {
	    // print(i, " ");
	    count = count + 1;
	    for (k = i+i;  k < numbers;  k = k+i)
	        sieve[k] = #t;
	}
    }
    count;
}

evals = evaluations() - evals;

now   = cputime();
secs  = now - then;

print("\r", count, " primes in the first ", numbers, " numbers\n");
print(evals, " nodes evaluated in ",
      secs, " seconds = ",
      round(evals / secs), " nodes/sec\n");