a(n) = 2*n^2 + 3*n + 3.

Terms

a(0) =3a(1) =8a(2) =17a(3) =30a(4) =47a(5) =68a(6) =93a(7) =122a(8) =155a(9) =192a(10) =233a(11) =278a(12) =327a(13) =380a(14) =437a(15) =498a(16) =563a(17) =632a(18) =705a(19) =782a(20) =863a(21) =948a(22) =1037a(23) =1130a(24) =1227a(25) =1328a(26) =1433a(27) =1542a(28) =1655a(29) =1772