code: function seq(to, from = 0, step = 1) {
    var result = [];
    var count = 0;
    if (to > from) for (let i = from; i < to; i += step) result[count++] = i;
    else           for (let i = from; i > to; i -= step) result[count++] = i;
  
    return result;
  }
docs: Create an array of a sequence of integers.