a(n) = 4*n^3 + 5.

Terms

a(0) =1a(1) =5a(2) =9a(3) =37a(4) =113a(5) =261a(6) =505a(7) =869a(8) =1377a(9) =2053a(10) =2921a(11) =4005a(12) =5329a(13) =6917a(14) =8793a(15) =10981a(16) =13505a(17) =16389a(18) =19657a(19) =23333a(20) =27441a(21) =32005a(22) =37049a(23) =42597a(24) =48673a(25) =55301a(26) =62505a(27) =70309a(28) =78737a(29) =87813