a(n) is the Wiener index of a tridon on n vertices.

Terms

a(0) =16a(1) =28a(2) =46a(3) =71a(4) =104a(5) =146a(6) =198a(7) =261a(8) =336a(9) =424a(10) =526a(11) =643a(12) =776a(13) =926a(14) =1094a(15) =1281a(16) =1488a(17) =1716a(18) =1966a(19) =2239a(20) =2536a(21) =2858a(22) =3206a(23) =3581a(24) =3984a(25) =4416a(26) =4878a(27) =5371a(28) =5896a(29) =6454