a(n) = (9*n + 1)^2.

Terms

a(0) =1a(1) =100a(2) =361a(3) =784a(4) =1369a(5) =2116a(6) =3025a(7) =4096a(8) =5329a(9) =6724a(10) =8281a(11) =10000a(12) =11881a(13) =13924a(14) =16129a(15) =18496a(16) =21025a(17) =23716a(18) =26569a(19) =29584a(20) =32761a(21) =36100a(22) =39601a(23) =43264a(24) =47089a(25) =51076a(26) =55225a(27) =59536a(28) =64009a(29) =68644