function TaylorPhi01() {
with (document.taylor01) {
  var A = parseInt(a.value);
  if (a.value == "") A = 0;
  var n = 1
  var fn1 = 1
  var fn2 = 1
  var fn3 = 2
  var fn4 = 3
  var i = 0
  var x = 0
  var x1 = 0
  var x2 = 0
  var pm = -1
  var ej = 1

  for(i = 0; i <= A; i++) {
    n++;
    x1 = (1 / fn1 / fn3) * ej;
    ej *= pm;
    x2 = (fn1 / fn2 / fn3 / fn4) * ej;
    x = x + x1 + x2;
    fn1 = fn2;
    fn2 = fn3; 
    fn3 = fn4;
    fn4 = fn2 + fn3;
  }
  xn.value = n
  f1.value = fn1
  f2.value = fn2
  f3.value = fn3
  f4.value = fn4
  s1.value = x1
  s2.value = x2
  s3.value = x
 }
}