a(n) = (7*n)^2.

Terms

a(0) =0a(1) =49a(2) =196a(3) =441a(4) =784a(5) =1225a(6) =1764a(7) =2401a(8) =3136a(9) =3969a(10) =4900a(11) =5929a(12) =7056a(13) =8281a(14) =9604a(15) =11025a(16) =12544a(17) =14161a(18) =15876a(19) =17689a(20) =19600a(21) =21609a(22) =23716a(23) =25921a(24) =28224a(25) =30625a(26) =33124a(27) =35721a(28) =38416a(29) =41209