9800*n^2-5740*n-4059.

Terms

a(0) =1a(1) =23661a(2) =66921a(3) =129781a(4) =212241a(5) =314301a(6) =435961a(7) =577221a(8) =738081a(9) =918541a(10) =1118601a(11) =1338261a(12) =1577521a(13) =1836381a(14) =2114841a(15) =2412901a(16) =2730561a(17) =3067821a(18) =3424681a(19) =3801141a(20) =4197201a(21) =4612861a(22) =5048121a(23) =5502981a(24) =5977441a(25) =6471501