a(n) = 4*n^3 - 3*n + 1.

Terms

a(0) =1a(1) =2a(2) =27a(3) =100a(4) =245a(5) =486a(6) =847a(7) =1352a(8) =2025a(9) =2890a(10) =3971a(11) =5292a(12) =6877a(13) =8750a(14) =10935a(15) =13456a(16) =16337a(17) =19602a(18) =23275a(19) =27380a(20) =31941a(21) =36982a(22) =42527a(23) =48600a(24) =55225a(25) =62426a(26) =70227a(27) =78652a(28) =87725a(29) =97470