a(n) = 4 + 8*n + 10*n^2 + 4*n^3.

Terms

a(0) =4a(1) =26a(2) =92a(3) =226a(4) =452a(5) =794a(6) =1276a(7) =1922a(8) =2756a(9) =3802a(10) =5084a(11) =6626a(12) =8452a(13) =10586a(14) =13052a(15) =15874a(16) =19076a(17) =22682a(18) =26716a(19) =31202a(20) =36164a(21) =41626a(22) =47612a(23) =54146a(24) =61252a(25) =68954a(26) =77276a(27) =86242a(28) =95876a(29) =106202