Sum of the Wiener indices of all trees having n vertices.

Terms

a(0) =0a(1) =1a(2) =4a(3) =19a(4) =54a(5) =180a(6) =508a(7) =1533a(8) =4332a(9) =13041a(10) =37492a(11) =111367a(12) =326636a(13) =968802a(14) =2858460a(15) =8483290a(16) =25113618a(17) =74512947a(18) =220885446a(19) =655274837a(20) =1943117294a(21) =5763235194a(22) =17089323366a(23) =50673594159a(24) =150232437482a(25) =445359235627