SOURCE

var ml4 = {};
ml4.opacityIn = [0,1];
ml4.scaleIn = [0.2, 1];
ml4.scaleOut = 3;
ml4.durationIn = 800;
ml4.durationOut = 600;
ml4.delay = 500;

anime.timeline({loop: true})
  .add({
    targets: '.ml4 .letters-1',
    opacity: ml4.opacityIn,
    scale: ml4.scaleIn,
    duration: ml4.durationIn
  }).add({
    targets: '.ml4 .letters-1',
    opacity: 0,
    scale: ml4.scaleOut,
    duration: ml4.durationOut,
    easing: "easeInExpo",
    delay: ml4.delay
  }).add({
    targets: '.ml4 .letters-2',
    opacity: ml4.opacityIn,
    scale: ml4.scaleIn,
    duration: ml4.durationIn
  }).add({
    targets: '.ml4 .letters-2',
    opacity: 0,
    scale: ml4.scaleOut,
    duration: ml4.durationOut,
    easing: "easeInExpo",
    delay: ml4.delay
  }).add({
    targets: '.ml4 .letters-3',
    opacity: ml4.opacityIn,
    scale: ml4.scaleIn,
    duration: ml4.durationIn
  }).add({
    targets: '.ml4 .letters-3',
    opacity: 0,
    scale: ml4.scaleOut,
    duration: ml4.durationOut,
    easing: "easeInExpo",
    delay: ml4.delay
  }).add({
    targets: '.ml4',
    opacity: 0,
    duration: 500,
    delay: 500
  });

<h1 class="ml4">
  <span class="letters letters-1">Ready</span>
  <span class="letters letters-2">Set</span>
  <span class="letters letters-3">Go!</span>
</h1>

<script src="https://cdnjs.cloudflare.com/ajax/libs/animejs/2.0.2/anime.min.js"></script>

.ml4 {
  position: relative;
  font-weight: 900;
  font-size: 4.5em;
}
.ml4 .letters {
  position: absolute;
  margin: auto;
  left: 0;
  top: 0.3em;
  right: 0;
  opacity: 0; 
}