a(n) = 15*n^2 - 13*n.

Terms

a(0) =0a(1) =2a(2) =34a(3) =96a(4) =188a(5) =310a(6) =462a(7) =644a(8) =856a(9) =1098a(10) =1370a(11) =1672a(12) =2004a(13) =2366a(14) =2758a(15) =3180a(16) =3632a(17) =4114a(18) =4626a(19) =5168a(20) =5740a(21) =6342a(22) =6974a(23) =7636a(24) =8328a(25) =9050a(26) =9802a(27) =10584a(28) =11396a(29) =12238