var k, A = []; for (k=2; k<=100; k++) { A[k] = 1; } for (m=2; m<=10; m++) { document.write('<br>' + m +'の倍数:'); for (k=2*m; k<=100; k+=m) { document.write(k + ','); A[k] = 0; } } document.write('<br><br>素数は...<br>'); for (k=2; k<=100; k++) { if (A[k] != 0) { document.write(k + ','); } }