a(n)=floor{square((1*n^0+1*n^1+2*n^2+4*n^3)/(1*n^0+2*n^1+1*n^2))}.

Terms

a(0) =4a(1) =22a(2) =66a(3) =137a(4) =238a(5) =370a(6) =533a(7) =727a(8) =953a(9) =1211a(10) =1500a(11) =1821a(12) =2174a(13) =2559a(14) =2976a(15) =3424a(16) =3905a(17) =4418a(18) =4962a(19) =5538a(20) =6147a(21) =6787a(22) =7460a(23) =8164a(24) =8900a(25) =9668a(26) =10469a(27) =11301a(28) =12165a(29) =13061