a(n) = 1681*n^2 - 984*n - 696.

Terms

a(0) =1a(1) =4060a(2) =11481a(3) =22264a(4) =36409a(5) =53916a(6) =74785a(7) =99016a(8) =126609a(9) =157564a(10) =191881a(11) =229560a(12) =270601a(13) =315004a(14) =362769a(15) =413896a(16) =468385a(17) =526236a(18) =587449a(19) =652024a(20) =719961a(21) =791260a(22) =865921a(23) =943944a(24) =1025329a(25) =1110076a(26) =1198185a(27) =1289656a(28) =1384489a(29) =1482684