a(n) = (2*n-1)^2 + (2*n+1)^2.

Terms

a(0) =2a(1) =10a(2) =34a(3) =74a(4) =130a(5) =202a(6) =290a(7) =394a(8) =514a(9) =650a(10) =802a(11) =970a(12) =1154a(13) =1354a(14) =1570a(15) =1802a(16) =2050a(17) =2314a(18) =2594a(19) =2890a(20) =3202a(21) =3530a(22) =3874a(23) =4234a(24) =4610a(25) =5002a(26) =5410a(27) =5834a(28) =6274a(29) =6730