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

Terms

a(0) =51a(1) =200a(2) =447a(3) =792a(4) =1235a(5) =1776a(6) =2415a(7) =3152a(8) =3987a(9) =4920a(10) =5951a(11) =7080a(12) =8307a(13) =9632a(14) =11055a(15) =12576a(16) =14195a(17) =15912a(18) =17727a(19) =19640a(20) =21651a(21) =23760a(22) =25967a(23) =28272a(24) =30675a(25) =33176a(26) =35775a(27) =38472a(28) =41267a(29) =44160