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

Terms

a(0) =27a(1) =104a(2) =231a(3) =408a(4) =635a(5) =912a(6) =1239a(7) =1616a(8) =2043a(9) =2520a(10) =3047a(11) =3624a(12) =4251a(13) =4928a(14) =5655a(15) =6432a(16) =7259a(17) =8136a(18) =9063a(19) =10040a(20) =11067a(21) =12144a(22) =13271a(23) =14448a(24) =15675a(25) =16952a(26) =18279a(27) =19656a(28) =21083a(29) =22560