a(n) = (15*n^2 + 9*n + 2)/2.

Terms

a(0) =1a(1) =13a(2) =40a(3) =82a(4) =139a(5) =211a(6) =298a(7) =400a(8) =517a(9) =649a(10) =796a(11) =958a(12) =1135a(13) =1327a(14) =1534a(15) =1756a(16) =1993a(17) =2245a(18) =2512a(19) =2794a(20) =3091a(21) =3403a(22) =3730a(23) =4072a(24) =4429a(25) =4801a(26) =5188a(27) =5590a(28) =6007a(29) =6439