a(n) = 625*n^2 + 25.

Terms

a(0) =650a(1) =2525a(2) =5650a(3) =10025a(4) =15650a(5) =22525a(6) =30650a(7) =40025a(8) =50650a(9) =62525a(10) =75650a(11) =90025a(12) =105650a(13) =122525a(14) =140650a(15) =160025a(16) =180650a(17) =202525a(18) =225650a(19) =250025a(20) =275650a(21) =302525a(22) =330650a(23) =360025a(24) =390650a(25) =422525a(26) =455650a(27) =490025a(28) =525650a(29) =562525