a(n) = 49*n^2 - 2*n.

Terms

a(0) =47a(1) =192a(2) =435a(3) =776a(4) =1215a(5) =1752a(6) =2387a(7) =3120a(8) =3951a(9) =4880a(10) =5907a(11) =7032a(12) =8255a(13) =9576a(14) =10995a(15) =12512a(16) =14127a(17) =15840a(18) =17651a(19) =19560a(20) =21567a(21) =23672a(22) =25875a(23) =28176a(24) =30575a(25) =33072a(26) =35667a(27) =38360a(28) =41151a(29) =44040