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

Terms

a(0) =5a(1) =25a(2) =61a(3) =113a(4) =181a(5) =265a(6) =365a(7) =481a(8) =613a(9) =761a(10) =925a(11) =1105a(12) =1301a(13) =1513a(14) =1741a(15) =1985a(16) =2245a(17) =2521a(18) =2813a(19) =3121a(20) =3445a(21) =3785a(22) =4141a(23) =4513a(24) =4901a(25) =5305a(26) =5725a(27) =6161a(28) =6613a(29) =7081