a(n) = 17*n^2.

Terms

a(0) =0a(1) =17a(2) =68a(3) =153a(4) =272a(5) =425a(6) =612a(7) =833a(8) =1088a(9) =1377a(10) =1700a(11) =2057a(12) =2448a(13) =2873a(14) =3332a(15) =3825a(16) =4352a(17) =4913a(18) =5508a(19) =6137a(20) =6800a(21) =7497a(22) =8228a(23) =8993a(24) =9792a(25) =10625a(26) =11492a(27) =12393a(28) =13328a(29) =14297