Number of chair trees constructed from n chairs.

Terms

a(0) =0a(1) =1a(2) =3a(3) =15a(4) =79a(5) =463a(6) =2842a(7) =18261a(8) =120834a(9) =819229a(10) =5658536a(11) =39685005a(12) =281826519a(13) =2022583829a(14) =14645875257a(15) =106873747884