Number of trees of diameter 7.

Terms

a(0) =1a(1) =3a(2) =14a(3) =42a(4) =128a(5) =334a(6) =850a(7) =2010a(8) =4625a(9) =10201a(10) =21990a(11) =46108a(12) =94912a(13) =191562a(14) =380933a(15) =746338a(16) =1444676a(17) =2763931a(18) =5235309a(19) =9822686a(20) =18275648a(21) =33734658a(22) =61826344a(23) =112550305a(24) =203627610a(25) =366267931a(26) =655261559a(27) =1166312530a(28) =2066048261a(29) =3643352362