a(n) = 16*n^3 + 10*n^2 + 4*n + 1.

Terms

a(0) =1a(1) =31a(2) =177a(3) =535a(4) =1201a(5) =2271a(6) =3841a(7) =6007a(8) =8865a(9) =12511a(10) =17041a(11) =22551a(12) =29137a(13) =36895a(14) =45921a(15) =56311a(16) =68161a(17) =81567a(18) =96625a(19) =113431a(20) =132081a(21) =152671a(22) =175297a(23) =200055a(24) =227041a(25) =256351a(26) =288081a(27) =322327a(28) =359185a(29) =398751