The hyper-Wiener index of the triangular graph T(n) (n >= 1).

Terms

a(0) =0a(1) =0a(2) =3a(3) =21a(4) =75a(5) =195a(6) =420a(7) =798a(8) =1386a(9) =2250a(10) =3465a(11) =5115a(12) =7293a(13) =10101a(14) =13650a(15) =18060a(16) =23460a(17) =29988a(18) =37791a(19) =47025a(20) =57855a(21) =70455a(22) =85008a(23) =101706a(24) =120750a(25) =142350a(26) =166725a(27) =194103a(28) =224721a(29) =258825