a(n) = 3*n^2 + 27*n + 1.

Terms

a(0) =31a(1) =67a(2) =109a(3) =157a(4) =211a(5) =271a(6) =337a(7) =409a(8) =487a(9) =571a(10) =661a(11) =757a(12) =859a(13) =967a(14) =1081a(15) =1201a(16) =1327a(17) =1459a(18) =1597a(19) =1741a(20) =1891a(21) =2047a(22) =2209a(23) =2377a(24) =2551a(25) =2731a(26) =2917a(27) =3109a(28) =3307a(29) =3511