def triangles(): li1=[1]; yield li1; count = 3; li2=[1,1]; while count <= 11: yield li2; li1 = li2; li2=[]; index=0; while index<count: if index==0: li2.append(1); elif index==count-1: li2.append(1); else: li2.append(li1[index] + li1[index-1]); index=index+1; count=count+1; return;