Hofstadter's Chaotic Q Sequence II

See Q Sequence.

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.node circle {
  fill: #fff;
  stroke: #000;
  stroke-width: 1px;
}

.node text {
  font: 11px sans-serif;
}

.node--internal text {
  text-shadow: 0 1px 0 #fff, 0 -1px 0 #fff, 1px 0 0 #fff, -1px 0 0 #fff;
}

.link {
  fill: none;
  stroke: #555;
  stroke-width: 1.5px;
  stroke-opacity: 0.4;
}

</style>
<svg width="1400" height="5500"></svg>
<script src="https://d3js.org/d3.v4.0.0-alpha.44.min.js"></script>
<script src="hofstadter.js"></script>
<script>

var svg = d3.select("svg"),
    width = +svg.attr("width"),
    height = +svg.attr("height"),
    padding = 50,
    node, link;

var tree, root,
    N = 201,
    y;

svg = svg
    .attr("width", width)
    .attr("height", height)
  .append("g")
    .attr("transform", "translate(" + padding / 2 + ",0)");

y = d3.scaleLinear().domain([0, N]).range([height, 0]);

/*
  Build Diagram G from algebratic function
*/
tree = d3.tree()
    .size([width - padding, height - padding]);

sequence = d3.range(N).map(function(d, i) {
  return d3.Hofstadter.function.Q(i);
});

data = sequence.slice(1).map(function(d, i) {
  var parent = (i === 0) ? "" : d;
  return {name: "" + (i + 1), parent: "" + parent};
});

root = d3.stratify()
       .id(function(d) { return d.name; })
       .parentId(function(d) { return d.parent; })
       (data);

tree(root);

/*
  Render tree of Diagram G.
*/
link = svg.selectAll(".link")
      .data(root.descendants().slice(1))
    .enter().append("path")
      .attr("class", "link")
      .attr("d", function(d) {
        return "M" + d.x + "," + y(+d.data.name)
            + "C" + (d.x + d.parent.x) / 2 + "," + y(+d.data.name)
            + " " + (d.x + d.parent.x) / 2 + "," + y(+d.parent.data.name)
            + " " + d.parent.x + "," + y(+d.parent.data.name);
      });

node = svg.selectAll(".node")
      .data(root.descendants())
    .enter().append("g")
      .attr("class", "node")
      .attr("transform", function(d) { return "translate(" + d.x + "," + y(+d.data.name) + ")"; })

node.append("circle")
    .attr("r", 12)

node.append("text")
    .attr("dy", "0.3em")
    .style("text-anchor", "middle")
    .text(function(d) { return d.id.substring(d.id.lastIndexOf(".") + 1); });
</script>

https://d3js.org/d3.v4.0.0-alpha.44.min.js