<form [formGroup]="myForm">
<div formArrayName="things">
<div *ngFor="let thing of things.controls; let i=index">
<label [for]="'input' + i">Thing {{i}}:</label>
<input type="text" [formControlName]="i" [name]="'input' + i" [id]="'input' + i" (keyup.enter)="" />
</div>
</div>
</form>