a(n) = n*(8*n+7).

Terms

a(0) =0a(1) =15a(2) =46a(3) =93a(4) =156a(5) =235a(6) =330a(7) =441a(8) =568a(9) =711a(10) =870a(11) =1045a(12) =1236a(13) =1443a(14) =1666a(15) =1905a(16) =2160a(17) =2431a(18) =2718a(19) =3021a(20) =3340a(21) =3675a(22) =4026a(23) =4393a(24) =4776a(25) =5175a(26) =5590a(27) =6021a(28) =6468a(29) =6931