The Wiener index of a chain of n triangles (i.e., joined like VVV..VV; here V is a triangle!).

Terms

a(0) =3a(1) =14a(2) =37a(3) =76a(4) =135a(5) =218a(6) =329a(7) =472a(8) =651a(9) =870a(10) =1133a(11) =1444a(12) =1807a(13) =2226a(14) =2705a(15) =3248a(16) =3859a(17) =4542a(18) =5301a(19) =6140a(20) =7063a(21) =8074a(22) =9177a(23) =10376a(24) =11675a(25) =13078a(26) =14589a(27) =16212a(28) =17951a(29) =19810