Chained Transitions

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    var svg = d3.select("body").append("svg")
      .attr("width", 500)
      .attr("height", 500)
    .append('g')

var data = d3.range(200).map(d => [Math.random()*d,Math.random()*d ])
    var xScale = d3.scaleLinear().domain(d3.extent(data.map(row=>row[0]))).range([0,960])
    var yScale = d3.scaleLinear().domain(d3.extent(data.map(row=>row[1]))).range([500,0])
		
   
    svg.selectAll("circle").data(data).enter().append("circle")
    	.attr('cx',d => xScale(d[0]))
      .attr('cy',d => yScale(d[1]))
      .attr('r', 11)
      .attr('fill', 'black')
    d3.selectAll("circle").transition()
    .delay(function(d, i) { return i * 25; })
    .on("start", function repeat() {
        d3.active(this)
        		.attr('cx',(d,i)=>xScale(d[0]/2))
            .attr('r',22)
            .style("fill", "blue")
        		.duration(1681)
          .transition()
        		.attr('cx',(d,i)=>xScale(d[0]+d[0]/2))
            .style("fill", "yellow")
        		.attr('r',5)
            .duration(1000)

});

</script>
</body>

https://d3js.org/d3.v4.min.js