[Vlasenko Fedor]

<script>
function* sequence(a, b) {
    while (true) {
        yield(a);
        a += b;
    }
}

var generator = sequence(10, 3);
document.write(generator.next().value + '<br>');
document.write(generator.next().value + '<br>');
document.write(generator.next().value + '<br>');
</script>

демонстрация